Async, Concurrency & Runtimes Packages
Async runtimes, concurrency primitives, and futures for writing non-blocking, parallel, and highly concurrent programs (Tokio, futures, asyncio helpers).
Packages in Async, Concurrency & Runtimes
Kind
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concurrently
Run multiple terminal commands in parallel, with color-coded output and cross-platform support.
Tokio
The async runtime powering most of Rust's networked, concurrent, and I/O-bound applications.
futures
The foundational Future, Stream, and Sink traits and combinators for zero-cost async Rust
RxJS
The standard library for composing asynchronous and event-based programs using observable sequences
p-limit
A tiny, battle-tested utility for running async functions with a strict concurrency limit.
async-trait
Type erasure for async fn in Rust traits, enabling async methods behind dyn dispatch.
Gunicorn
A fast, lightweight pre-fork WSGI and ASGI HTTP server for running Python web apps in production on UNIX.
websockets
Build correct, fast WebSocket servers and clients in Python with asyncio, threading, or Sans-I/O APIs.
async-mutex
Mutex and semaphore primitives for synchronizing async workflows in JavaScript and TypeScript.
once_cell
Single-assignment cells and lazy statics for Rust, without macros or unsafe code
tokio-tungstenite
Asynchronous, Tokio-native WebSocket streams built on tungstenite
Tower
Modular, reusable Rust components for building async network clients and servers
async
Higher-order async utility functions for callback, async/await, and promise-based control flow in Node.js and the browser.
rayon
Simple, guaranteed data-race-free work-stealing parallelism for Rust — turn sequential iterators parallel by changing one call.
p-queue
Promise queue with concurrency control, interval-based rate limiting, and priority scheduling for async tasks.
AnyIO
High-level async concurrency and networking API that runs on both asyncio and Trio
DashMap
A blazing-fast concurrent HashMap for Rust that shards state across locks instead of using one global RwLock.
filelock
A platform-independent file lock for Python that supports the with-statement.
Effect
A TypeScript library and ecosystem for building robust, type-safe, concurrent applications with a full functional effect system
async-stream
Build asynchronous streams in Rust using async/await notation instead of hand-written state machines
p-map
Map over promises concurrently, with controlled concurrency, backpressure, abort signals, and error aggregation.
cross-spawn
A cross-platform drop-in replacement for Node's spawn and spawnSync that fixes Windows-only child_process bugs.
parking_lot
A faster, smaller drop-in replacement for Rust's standard library Mutex, RwLock, Condvar, and Once.
greenlet
Lightweight in-process coroutines for cooperative concurrency in Python
