Asynchronous GitHub Repositories (2026) · Open Source Tools

A runtime for writing reliable asynchronous applications with Rust. Provides I/O, networking, scheduling, timers, ...

Asynchronous Python client for WLED

Framework for quickly creating connected applications in Kotlin with minimal effort

Production-ready C++ Asynchronous Framework with rich functionality

An Intuitive Event-Driven Reactive Programming Library for Java

Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed.

Non-Blocking Reactive Foundation for the JVM

Awaitility is a small Java DSL for synchronizing asynchronous operations

A high-performance web server for Ruby, supporting HTTP/1, HTTP/2 and TLS.

Next-gen compile-time-checked builder generator, named function's arguments, and more!

Easy to use C++17 HTTP Server with no compromise on performances. https://matt-42.github.io/lithium

Add asynchronous RPC services to your multiplatform applications.

Non-blocking external commands in Go with streaming output

Full-featured async (tokio-based) postgres connection pool (like r2d2)

A high-performance Python SDK for building real-time WhatsApp applications with a Go-powered core, event-driven APIs, and production-ready reliability.

Queue plugin for CakePHP - simple, pure PHP and without dependencies.

Spec-driven framework for composable applications in Rust.

This crate provides concurrency control and async coordination primitives that are runtime agnostic.

A data-oriented C# Discord library, focused on high-performance concurrency and robust design.

Implementation of blocking (IO-Bound) cancellable java.util.concurrent.CompletionStage and related extensions to java.util.concurrent.ExecutorService-s