diff --git a/libraries/executors/README.md b/libraries/executors/README.md
new file mode 100644
index 00000000..5f405a39
--- /dev/null
+++ b/libraries/executors/README.md
@@ -0,0 +1,3 @@
+# Executors API
+
+The Executors API provides an interface for main thread and background thread executors.
diff --git a/libraries/executors/build.gradle b/libraries/executors/build.gradle
new file mode 100644
index 00000000..7bb43400
--- /dev/null
+++ b/libraries/executors/build.gradle
@@ -0,0 +1,5 @@
+setUpLibrary(project)
+
+dependencies {
+	implementation 'com.google.code.gson:gson:2.8.0'
+}
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/build.gradle b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/gradle.properties b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/gradle.properties
new file mode 100644
index 00000000..c30b8b4f
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/gradle.properties
@@ -0,0 +1,6 @@
+min_mc_version = 1.7.6-pre1
+max_mc_version = 1.7.10
+minecraft_dependency = >=1.7.6-rc.1 <=1.7.10
+
+minecraft_version = 1.7.10
+nests_build = 6
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
new file mode 100644
index 00000000..10e766ed
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
@@ -0,0 +1,37 @@
+package net.ornithemc.osl.executors.impl.mixin.client;
+
+import java.util.concurrent.Executor;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.google.common.util.concurrent.ListenableFuture;
+
+import net.minecraft.client.Minecraft;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(Minecraft.class)
+public class MinecraftMixin implements Executor {
+
+	@Shadow
+	private ListenableFuture<?> executeTask(Runnable task) { return null; }
+
+	@Override
+	public void execute(Runnable command) {
+		this.executeTask(command);
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
new file mode 100644
index 00000000..367e37fb
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
@@ -0,0 +1,87 @@
+package net.ornithemc.osl.executors.impl.mixin.common;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.profiler.Profiler;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements MainThreadExecutor {
+
+	@Shadow @Final
+	private Profiler profiler;
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "tickWorlds",
+		at  = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.profiler.push("scheduledExecutables");
+		this.runPendingTasks();
+		this.profiler.pop();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+}
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
new file mode 100644
index 00000000..bc602418
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
@@ -0,0 +1,24 @@
+package net.ornithemc.osl.executors.impl.mixin.server;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin {
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/fabric.mod.json b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..ade7144b
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-executors",
+  "version": "0.1.0-alpha.1+mc1.7.6-pre1-mc1.7.10",
+  "environment": "*",
+  "mixins": [
+    "osl.executors.mixins.json"
+  ],
+  "accessWidener": "osl.executors.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.17.3",
+    "minecraft": "\u003e\u003d1.7.6-rc.1 \u003c\u003d1.7.10",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Executors",
+  "description": "Interface for main thread and background threads executors.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/osl.executors.classtweaker b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/osl.executors.classtweaker
new file mode 100644
index 00000000..30321462
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/osl.executors.classtweaker
@@ -0,0 +1,4 @@
+classTweaker	v1	named
+
+transitive-inject-interface	net/minecraft/client/Minecraft	java/util/concurrent/Executor
+transitive-inject-interface	net/minecraft/server/MinecraftServer	net/ornithemc/osl/executors/api/MainThreadExecutor
\ No newline at end of file
diff --git a/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/osl.executors.mixins.json b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/osl.executors.mixins.json
new file mode 100644
index 00000000..40105b6d
--- /dev/null
+++ b/libraries/executors/executors-mc1.7.6-pre1-mc1.7.10/src/main/resources/osl.executors.mixins.json
@@ -0,0 +1,18 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.executors.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.MinecraftServerMixin"
+	],
+	"client": [
+		"client.MinecraftMixin"
+	],
+	"server": [
+		"server.MinecraftServerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/build.gradle b/libraries/executors/executors-mc12w18a-mc1.7.5/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/gradle.properties b/libraries/executors/executors-mc12w18a-mc1.7.5/gradle.properties
new file mode 100644
index 00000000..b032be5a
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/gradle.properties
@@ -0,0 +1,6 @@
+min_mc_version = 12w18a
+max_mc_version = 1.7.5
+minecraft_dependency = >=1.3-alpha.12.18.a <=1.7.5
+
+minecraft_version = 1.7.5
+nests_build = 5
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
new file mode 100644
index 00000000..96ef6678
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
@@ -0,0 +1,92 @@
+package net.ornithemc.osl.executors.impl.mixin.client;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.Minecraft;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(Minecraft.class)
+public class MinecraftMixin implements MainThreadExecutor {
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "runGame",
+		at  = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/client/TickTimer;advance()V",
+			shift = Shift.AFTER
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.runPendingTasks();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
new file mode 100644
index 00000000..00d33439
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
@@ -0,0 +1,85 @@
+package net.ornithemc.osl.executors.impl.mixin.common;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements MainThreadExecutor {
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "tick",
+		at  = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/server/MinecraftServer;ticks:I",
+			opcode = Opcodes.PUTFIELD,
+			shift = Shift.AFTER
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.runPendingTasks();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+}
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
new file mode 100644
index 00000000..bc602418
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
@@ -0,0 +1,24 @@
+package net.ornithemc.osl.executors.impl.mixin.server;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin {
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/fabric.mod.json b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..a894b2e9
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-executors",
+  "version": "0.1.0-alpha.1+mc12w18a-mc1.7.5",
+  "environment": "*",
+  "mixins": [
+    "osl.executors.mixins.json"
+  ],
+  "accessWidener": "osl.executors.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.17.3",
+    "minecraft": "\u003e\u003d1.3-alpha.12.18.a \u003c\u003d1.7.5",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Executors",
+  "description": "Interface for main thread and background threads executors.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/osl.executors.classtweaker b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/osl.executors.classtweaker
new file mode 100644
index 00000000..a8205231
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/osl.executors.classtweaker
@@ -0,0 +1,4 @@
+classTweaker	v1	named
+
+transitive-inject-interface	net/minecraft/client/Minecraft	net/ornithemc/osl/executors/api/MainThreadExecutor
+transitive-inject-interface	net/minecraft/server/MinecraftServer	net/ornithemc/osl/executors/api/MainThreadExecutor
\ No newline at end of file
diff --git a/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/osl.executors.mixins.json b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/osl.executors.mixins.json
new file mode 100644
index 00000000..40105b6d
--- /dev/null
+++ b/libraries/executors/executors-mc12w18a-mc1.7.5/src/main/resources/osl.executors.mixins.json
@@ -0,0 +1,18 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.executors.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.MinecraftServerMixin"
+	],
+	"client": [
+		"client.MinecraftMixin"
+	],
+	"server": [
+		"server.MinecraftServerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/build.gradle b/libraries/executors/executors-mc14w02a-mc14w06b/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/gradle.properties b/libraries/executors/executors-mc14w02a-mc14w06b/gradle.properties
new file mode 100644
index 00000000..51f199a5
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/gradle.properties
@@ -0,0 +1,6 @@
+min_mc_version = 14w02a
+max_mc_version = 14w06b
+minecraft_dependency = >=1.8-alpha.14.2.a <=18.alpha.14.6.b
+
+minecraft_version = 14w06b
+nests_build = 5
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
new file mode 100644
index 00000000..8e4138a2
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
@@ -0,0 +1,100 @@
+package net.ornithemc.osl.executors.impl.mixin.client;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.util.profiler.Profiler;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(Minecraft.class)
+public class MinecraftMixin implements MainThreadExecutor {
+
+	@Shadow @Final
+	private Profiler profiler;
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "runGame",
+		at  = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/client/TickTimer;advance()V",
+			shift = Shift.AFTER
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.profiler.push("scheduledExecutables");
+		this.runPendingTasks();
+		this.profiler.pop();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
new file mode 100644
index 00000000..367e37fb
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
@@ -0,0 +1,87 @@
+package net.ornithemc.osl.executors.impl.mixin.common;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.profiler.Profiler;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements MainThreadExecutor {
+
+	@Shadow @Final
+	private Profiler profiler;
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "tickWorlds",
+		at  = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.profiler.push("scheduledExecutables");
+		this.runPendingTasks();
+		this.profiler.pop();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+}
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
new file mode 100644
index 00000000..bc602418
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
@@ -0,0 +1,24 @@
+package net.ornithemc.osl.executors.impl.mixin.server;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin {
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/fabric.mod.json b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..aaa09668
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-executors",
+  "version": "0.1.0-alpha.1+mc14w02a-mc14w06b",
+  "environment": "*",
+  "mixins": [
+    "osl.executors.mixins.json"
+  ],
+  "accessWidener": "osl.executors.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.17.3",
+    "minecraft": "\u003e\u003d1.8-alpha.14.2.a \u003c\u003d18.alpha.14.6.b",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Executors",
+  "description": "Interface for main thread and background threads executors.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/osl.executors.classtweaker b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/osl.executors.classtweaker
new file mode 100644
index 00000000..a8205231
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/osl.executors.classtweaker
@@ -0,0 +1,4 @@
+classTweaker	v1	named
+
+transitive-inject-interface	net/minecraft/client/Minecraft	net/ornithemc/osl/executors/api/MainThreadExecutor
+transitive-inject-interface	net/minecraft/server/MinecraftServer	net/ornithemc/osl/executors/api/MainThreadExecutor
\ No newline at end of file
diff --git a/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/osl.executors.mixins.json b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/osl.executors.mixins.json
new file mode 100644
index 00000000..40105b6d
--- /dev/null
+++ b/libraries/executors/executors-mc14w02a-mc14w06b/src/main/resources/osl.executors.mixins.json
@@ -0,0 +1,18 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.executors.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.MinecraftServerMixin"
+	],
+	"client": [
+		"client.MinecraftMixin"
+	],
+	"server": [
+		"server.MinecraftServerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/build.gradle b/libraries/executors/executors-mc14w07a-mc14w20b/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/gradle.properties b/libraries/executors/executors-mc14w07a-mc14w20b/gradle.properties
new file mode 100644
index 00000000..670a8e2e
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/gradle.properties
@@ -0,0 +1,6 @@
+min_mc_version = 14w07a
+max_mc_version = 14w20b
+minecraft_dependency = >=1.8-alpha.14.7.a <=1.8-alpha.14.20.b
+
+minecraft_version = 14w20b
+nests_build = 5
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
new file mode 100644
index 00000000..10e766ed
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
@@ -0,0 +1,37 @@
+package net.ornithemc.osl.executors.impl.mixin.client;
+
+import java.util.concurrent.Executor;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.google.common.util.concurrent.ListenableFuture;
+
+import net.minecraft.client.Minecraft;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(Minecraft.class)
+public class MinecraftMixin implements Executor {
+
+	@Shadow
+	private ListenableFuture<?> executeTask(Runnable task) { return null; }
+
+	@Override
+	public void execute(Runnable command) {
+		this.executeTask(command);
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
new file mode 100644
index 00000000..367e37fb
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
@@ -0,0 +1,87 @@
+package net.ornithemc.osl.executors.impl.mixin.common;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.profiler.Profiler;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements MainThreadExecutor {
+
+	@Shadow @Final
+	private Profiler profiler;
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "tickWorlds",
+		at  = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.profiler.push("scheduledExecutables");
+		this.runPendingTasks();
+		this.profiler.pop();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+}
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
new file mode 100644
index 00000000..bc602418
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
@@ -0,0 +1,24 @@
+package net.ornithemc.osl.executors.impl.mixin.server;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin {
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/fabric.mod.json b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..e4a7da74
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-executors",
+  "version": "0.1.0-alpha.1+mc14w07a-mc14w20b",
+  "environment": "*",
+  "mixins": [
+    "osl.executors.mixins.json"
+  ],
+  "accessWidener": "osl.executors.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.17.3",
+    "minecraft": "\u003e\u003d1.8-alpha.14.7.a \u003c\u003d1.8-alpha.14.20.b",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Executors",
+  "description": "Interface for main thread and background threads executors.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/osl.executors.classtweaker b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/osl.executors.classtweaker
new file mode 100644
index 00000000..30321462
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/osl.executors.classtweaker
@@ -0,0 +1,4 @@
+classTweaker	v1	named
+
+transitive-inject-interface	net/minecraft/client/Minecraft	java/util/concurrent/Executor
+transitive-inject-interface	net/minecraft/server/MinecraftServer	net/ornithemc/osl/executors/api/MainThreadExecutor
\ No newline at end of file
diff --git a/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/osl.executors.mixins.json b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/osl.executors.mixins.json
new file mode 100644
index 00000000..40105b6d
--- /dev/null
+++ b/libraries/executors/executors-mc14w07a-mc14w20b/src/main/resources/osl.executors.mixins.json
@@ -0,0 +1,18 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.executors.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.MinecraftServerMixin"
+	],
+	"client": [
+		"client.MinecraftMixin"
+	],
+	"server": [
+		"server.MinecraftServerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/build.gradle b/libraries/executors/executors-mc14w21a-mc1.13.2/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/gradle.properties b/libraries/executors/executors-mc14w21a-mc1.13.2/gradle.properties
new file mode 100644
index 00000000..4051b4f4
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/gradle.properties
@@ -0,0 +1,5 @@
+min_mc_version = 14w21a
+max_mc_version = 1.13.2
+minecraft_dependency = >=1.8-alpha.14.21.a <=1.13.2
+
+minecraft_version = 1.13.2
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
new file mode 100644
index 00000000..f25fed9e
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
@@ -0,0 +1,32 @@
+package net.ornithemc.osl.executors.impl.mixin.client;
+
+import java.util.concurrent.Executor;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.util.BlockableEventLoop;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(Minecraft.class)
+public class MinecraftMixin implements Executor {
+
+	@Override
+	public void execute(Runnable command) {
+		((BlockableEventLoop) this).executeTask(command);
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
new file mode 100644
index 00000000..54c32ee6
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/common/MinecraftServerMixin.java
@@ -0,0 +1,17 @@
+package net.ornithemc.osl.executors.impl.mixin.common;
+
+import java.util.concurrent.Executor;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.BlockableEventLoop;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements Executor {
+
+	@Override
+	public void execute(Runnable command) {
+		((BlockableEventLoop) this).executeTask(command);
+	}
+}
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
new file mode 100644
index 00000000..bc602418
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
@@ -0,0 +1,24 @@
+package net.ornithemc.osl.executors.impl.mixin.server;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin {
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/fabric.mod.json b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..3bf4c119
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-executors",
+  "version": "0.1.0-alpha.1+mc14w21a-mc1.13.2",
+  "environment": "*",
+  "mixins": [
+    "osl.executors.mixins.json"
+  ],
+  "accessWidener": "osl.executors.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.17.3",
+    "minecraft": "\u003e\u003d1.8-alpha.14.21.a \u003c\u003d1.13.2",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Executors",
+  "description": "Interface for main thread and background threads executors.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/osl.executors.classtweaker b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/osl.executors.classtweaker
new file mode 100644
index 00000000..3d2647fe
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/osl.executors.classtweaker
@@ -0,0 +1,4 @@
+classTweaker	v1	named
+
+transitive-inject-interface	net/minecraft/client/Minecraft	java/util/concurrent/Executor
+transitive-inject-interface	net/minecraft/server/MinecraftServer	java/util/concurrent/Executor
\ No newline at end of file
diff --git a/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/osl.executors.mixins.json b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/osl.executors.mixins.json
new file mode 100644
index 00000000..40105b6d
--- /dev/null
+++ b/libraries/executors/executors-mc14w21a-mc1.13.2/src/main/resources/osl.executors.mixins.json
@@ -0,0 +1,18 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.executors.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.MinecraftServerMixin"
+	],
+	"client": [
+		"client.MinecraftMixin"
+	],
+	"server": [
+		"server.MinecraftServerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/executors/executors-mcb1.9-pre3-mc12w17a/build.gradle b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/executors/executors-mcb1.9-pre3-mc12w17a/gradle.properties b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/gradle.properties
new file mode 100644
index 00000000..25342b20
--- /dev/null
+++ b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/gradle.properties
@@ -0,0 +1,7 @@
+min_mc_version = b1.9-pre3-1350
+max_mc_version = 12w17a
+minecraft_dependency = >=1.0.0-beta.9.0.3 <=1.3-alpha.12.17.a
+
+minecraft_version = 12w17a
+client_nests_build = 10
+server_nests_build = 5
diff --git a/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
new file mode 100644
index 00000000..96ef6678
--- /dev/null
+++ b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
@@ -0,0 +1,92 @@
+package net.ornithemc.osl.executors.impl.mixin.client;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.Minecraft;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(Minecraft.class)
+public class MinecraftMixin implements MainThreadExecutor {
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "runGame",
+		at  = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/client/TickTimer;advance()V",
+			shift = Shift.AFTER
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.runPendingTasks();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
new file mode 100644
index 00000000..8c2556b6
--- /dev/null
+++ b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
@@ -0,0 +1,95 @@
+package net.ornithemc.osl.executors.impl.mixin.server;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements MainThreadExecutor {
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "tick",
+		at  = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/server/MinecraftServer;ticks:I",
+			opcode = Opcodes.PUTFIELD,
+			shift = Shift.AFTER
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.runPendingTasks();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/fabric.mod.json b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..905e0934
--- /dev/null
+++ b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-executors",
+  "version": "0.1.0-alpha.1+mcb1.9-pre3-1350-mc12w17a",
+  "environment": "*",
+  "mixins": [
+    "osl.executors.mixins.json"
+  ],
+  "accessWidener": "osl.executors.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.17.3",
+    "minecraft": "\u003e\u003d1.0.0-beta.9.0.3 \u003c\u003d1.3-alpha.12.17.a",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Executors",
+  "description": "Interface for main thread and background threads executors.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/osl.executors.classtweaker b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/osl.executors.classtweaker
new file mode 100644
index 00000000..a8205231
--- /dev/null
+++ b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/osl.executors.classtweaker
@@ -0,0 +1,4 @@
+classTweaker	v1	named
+
+transitive-inject-interface	net/minecraft/client/Minecraft	net/ornithemc/osl/executors/api/MainThreadExecutor
+transitive-inject-interface	net/minecraft/server/MinecraftServer	net/ornithemc/osl/executors/api/MainThreadExecutor
\ No newline at end of file
diff --git a/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/osl.executors.mixins.json b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/osl.executors.mixins.json
new file mode 100644
index 00000000..8b64f37d
--- /dev/null
+++ b/libraries/executors/executors-mcb1.9-pre3-mc12w17a/src/main/resources/osl.executors.mixins.json
@@ -0,0 +1,17 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.executors.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+	],
+	"client": [
+		"client.MinecraftMixin"
+	],
+	"server": [
+		"server.MinecraftServerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/build.gradle b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/gradle.properties b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/gradle.properties
new file mode 100644
index 00000000..e754804b
--- /dev/null
+++ b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/gradle.properties
@@ -0,0 +1,11 @@
+min_mc_version = in-20100128-2304
+max_mc_version = b1.9-pre2
+minecraft_dependency = >=0.31.20100128-2304 <=1.0.0-beta.9.0.2
+
+minecraft_version = b1.9-pre2
+client_raven_build = 1
+server_raven_build = 1
+client_sparrow_build = 1
+server_sparrow_build = 1
+client_nests_build = 8
+server_nests_build = 5
diff --git a/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
new file mode 100644
index 00000000..cb3d0076
--- /dev/null
+++ b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/java/net/ornithemc/osl/executors/impl/mixin/client/MinecraftMixin.java
@@ -0,0 +1,92 @@
+package net.ornithemc.osl.executors.impl.mixin.client;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.Minecraft;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(Minecraft.class)
+public class MinecraftMixin implements MainThreadExecutor {
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "run",
+		at  = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/client/TickTimer;advance()V",
+			shift = Shift.AFTER
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.runPendingTasks();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
new file mode 100644
index 00000000..8c2556b6
--- /dev/null
+++ b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/java/net/ornithemc/osl/executors/impl/mixin/server/MinecraftServerMixin.java
@@ -0,0 +1,95 @@
+package net.ornithemc.osl.executors.impl.mixin.server;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.server.MinecraftServer;
+
+import net.ornithemc.osl.executors.api.MainThreadExecutor;
+import net.ornithemc.osl.executors.impl.Executors;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements MainThreadExecutor {
+
+	@Unique
+	private final Queue<Runnable> pendingTasks = new ArrayDeque<>();
+
+	@Unique
+	private Thread thread;
+
+	@Inject(
+		method = "run",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private void osl$executors$setThread(CallbackInfo ci) {
+		this.thread = Thread.currentThread();
+	}
+
+	@Override
+	public void execute(Runnable command) {
+		if (this.isOnSameThread()) {
+			command.run();
+		} else {
+			synchronized (this.pendingTasks) {
+				this.pendingTasks.add(command);
+			}
+		}
+	}
+
+	@Override
+	public boolean isOnSameThread() {
+		return Thread.currentThread() == this.thread;
+	}
+
+	@Inject(
+		method = "tick",
+		at  = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/server/MinecraftServer;ticks:I",
+			opcode = Opcodes.PUTFIELD,
+			shift = Shift.AFTER
+		)
+	)
+	private void osl$executors$runPendingTasks(CallbackInfo ci) {
+		this.runPendingTasks();
+	}
+
+	@Unique
+	private void runPendingTasks() {
+		synchronized (this.pendingTasks) {
+			while (!this.pendingTasks.isEmpty()) {
+				this.runTask(this.pendingTasks.poll());
+			}
+		}
+	}
+
+	@Unique
+	private void runTask(Runnable task) {
+		try {
+			task.run();
+		} catch (Throwable t) {
+			Executors.LOGGER.fatal("Error running task", t);
+		}
+	}
+
+	@Inject(
+		method = "shutdown",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$executors$shutdownBackgroundExecutor(CallbackInfo ci) {
+		Executors.shutdownBackgroundExecutor();
+	}
+}
diff --git a/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/fabric.mod.json b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..e2fd3e97
--- /dev/null
+++ b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-executors",
+  "version": "0.1.0-alpha.1+mcin-20100128-2304-mcb1.9-pre2",
+  "environment": "*",
+  "mixins": [
+    "osl.executors.mixins.json"
+  ],
+  "accessWidener": "osl.executors.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.17.3",
+    "minecraft": "\u003e\u003d0.31.20100128-2304 \u003c\u003d1.0.0-beta.9.0.2",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Executors",
+  "description": "Interface for main thread and background threads executors.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/osl.executors.classtweaker b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/osl.executors.classtweaker
new file mode 100644
index 00000000..a8205231
--- /dev/null
+++ b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/osl.executors.classtweaker
@@ -0,0 +1,4 @@
+classTweaker	v1	named
+
+transitive-inject-interface	net/minecraft/client/Minecraft	net/ornithemc/osl/executors/api/MainThreadExecutor
+transitive-inject-interface	net/minecraft/server/MinecraftServer	net/ornithemc/osl/executors/api/MainThreadExecutor
\ No newline at end of file
diff --git a/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/osl.executors.mixins.json b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/osl.executors.mixins.json
new file mode 100644
index 00000000..8b64f37d
--- /dev/null
+++ b/libraries/executors/executors-mcin-20100128-2304-mcb1.9-pre2/src/main/resources/osl.executors.mixins.json
@@ -0,0 +1,17 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.executors.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+	],
+	"client": [
+		"client.MinecraftMixin"
+	],
+	"server": [
+		"server.MinecraftServerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/executors/gradle.properties b/libraries/executors/gradle.properties
new file mode 100644
index 00000000..5c1603a5
--- /dev/null
+++ b/libraries/executors/gradle.properties
@@ -0,0 +1,6 @@
+library_id = executors
+library_name = Executors
+library_description = Interface for main thread and background threads executors.
+library_version = 0.1.0-alpha.1
+
+osl_dependencies = core:>=0.7.0
diff --git a/libraries/executors/src/main/java/net/ornithemc/osl/executors/api/BackgroundExecutor.java b/libraries/executors/src/main/java/net/ornithemc/osl/executors/api/BackgroundExecutor.java
new file mode 100644
index 00000000..50190faa
--- /dev/null
+++ b/libraries/executors/src/main/java/net/ornithemc/osl/executors/api/BackgroundExecutor.java
@@ -0,0 +1,28 @@
+package net.ornithemc.osl.executors.api;
+
+import java.util.concurrent.Executor;
+
+import net.ornithemc.osl.executors.impl.Executors;
+
+/**
+ * A utility class for accessing the background executor.
+ * 
+ * <p>
+ * The background executor can be used to run tasks asynchronously.
+ * This will take load off the game's main thread, which can prevent
+ * excessive slow-downs.
+ * 
+ * <p>
+ * Do note that operations done on background threads must be thread-
+ * safe. Do NOT modify the world or render state in background tasks,
+ * as this will inevitably lead to save corruption and crashes.
+ */
+public final class BackgroundExecutor {
+
+	/**
+	 * @return the background executor.
+	 */
+	public static Executor get() {
+		return Executors.backgroundExecutor();
+	}
+}
diff --git a/libraries/executors/src/main/java/net/ornithemc/osl/executors/api/MainThreadExecutor.java b/libraries/executors/src/main/java/net/ornithemc/osl/executors/api/MainThreadExecutor.java
new file mode 100644
index 00000000..0143dba5
--- /dev/null
+++ b/libraries/executors/src/main/java/net/ornithemc/osl/executors/api/MainThreadExecutor.java
@@ -0,0 +1,12 @@
+package net.ornithemc.osl.executors.api;
+
+import java.util.concurrent.Executor;
+
+public interface MainThreadExecutor extends Executor {
+
+	/**
+	 * @return whether this executor is on the same thread as the caller.
+	 */
+	boolean isOnSameThread();
+
+}
diff --git a/libraries/executors/src/main/java/net/ornithemc/osl/executors/impl/Executors.java b/libraries/executors/src/main/java/net/ornithemc/osl/executors/impl/Executors.java
new file mode 100644
index 00000000..3a6b9275
--- /dev/null
+++ b/libraries/executors/src/main/java/net/ornithemc/osl/executors/impl/Executors.java
@@ -0,0 +1,69 @@
+package net.ornithemc.osl.executors.impl;
+
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.ForkJoinWorkerThread;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public final class Executors {
+
+	public static final Logger LOGGER = LogManager.getLogger("OSL|Executors");
+
+	private static final ExecutorService BACKGROUND_EXECUTOR = makeExecutor("Main");
+
+	private static ExecutorService makeExecutor(String name) {
+		int maxBackgroundThreads = 7;
+		int backgroundThreads = Math.min(Runtime.getRuntime().availableProcessors() - 1, maxBackgroundThreads);
+
+		AtomicInteger workerCount = new AtomicInteger(1);
+
+		return new ForkJoinPool(backgroundThreads, forkJoinPool -> {
+			ForkJoinWorkerThread backgroundThread = new ForkJoinWorkerThread(forkJoinPool) {
+
+				@Override
+				protected void onTermination(Throwable exception) {
+					if (exception != null) {
+						LOGGER.warn("{} died", this.getName(), exception);
+					} else {
+						LOGGER.debug("{} shutdown", this.getName());
+					}
+
+					super.onTermination(exception);
+				}
+			};
+			backgroundThread.setName("Worker-" + workerCount.getAndIncrement());
+			return backgroundThread;
+		}, Executors::handleBackgroundThreadException, true);
+	}
+
+	private static void handleBackgroundThreadException(Thread thread, Throwable exception) {
+		if (exception instanceof CompletionException) {
+			exception = exception.getCause();
+		}
+
+		LOGGER.error("Caught exception in thread {}", thread, exception);
+	}
+
+	public static Executor backgroundExecutor() {
+		return BACKGROUND_EXECUTOR;
+	}
+
+	public static void shutdownBackgroundExecutor() {
+		BACKGROUND_EXECUTOR.shutdown();
+
+		try {
+			boolean terminated = BACKGROUND_EXECUTOR.awaitTermination(3, TimeUnit.SECONDS);
+
+			if (!terminated) {
+				BACKGROUND_EXECUTOR.shutdownNow();
+			}
+		} catch (InterruptedException ignored) {
+		}
+	}
+}
diff --git a/settings.gradle b/settings.gradle
index 01f6cf8f..e0a07c50 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -39,6 +39,15 @@ include ':libraries:entrypoints'
 include ':libraries:entrypoints:entrypoints-mcin-20091223-1459-mc1.5.2'
 include ':libraries:entrypoints:entrypoints-mc13w16a-mc1.14.4'
 
+include ':libraries:executors'
+include ':libraries:executors:executors-mcin-20100128-2304-mcb1.9-pre2'
+include ':libraries:executors:executors-mcb1.9-pre3-mc12w17a'
+include ':libraries:executors:executors-mc12w18a-mc1.7.5'
+include ':libraries:executors:executors-mc1.7.6-pre1-mc1.7.10'
+include ':libraries:executors:executors-mc14w02a-mc14w06b'
+include ':libraries:executors:executors-mc14w07a-mc14w20b'
+include ':libraries:executors:executors-mc14w21a-mc1.13.2'
+
 include ':libraries:keybinds'
 include ':libraries:keybinds:keybinds-mcc0.0.23a_01-mcb1.7.3'
 include ':libraries:keybinds:keybinds-mcb1.8-pre1-mc1.6.4'