Open-source alternatives to Trio

Handy is a C++11 network server framework and event-driven networking engine designed for building high-performance concurrent TCP and UDP servers. It functions as an asynchronous I/O library and an HTTP server implementation that separates asynchronous network I/O from synchronous business logic to simplify server development. The framework distinguishes itself by utilizing platform-specific event notifications to manage millions of simultaneous network connections and providing an SSL/TLS network wrapper for encrypted asynchronous data transmission. It implements a half-sync/half-async proc

conc is a Go concurrency library and structured concurrency framework providing primitives for managing parallel tasks, mapping slices, and collecting results. It implements a system for spawning scoped tasks to ensure all child processes complete before their parent exits. The library includes a goroutine pool manager to limit active concurrent processes and a panic-safe task runner that catches panics in goroutines and propagates stack traces to the parent. It also provides a concurrent map-reduce tool for transforming data slices and processing streams in parallel while maintaining the ori

Twisted is an event-driven networking engine for Python that provides a framework for building asynchronous network applications. At its core, it uses a reactor-based event loop to drive all input and output, dispatching callbacks in a single thread without blocking. The library implements a deferred promise chain for composing asynchronous logic, along with a protocol and factory pattern that separates connection state management from protocol handling, enabling reusable handlers for different network protocols. The framework supports multiple event loops across platforms, including select,

This project is a framework for building concurrent, event-driven applications in Ruby. It provides a core engine that orchestrates non-blocking input and output operations, allowing developers to handle high-volume network traffic and system tasks without the complexity of traditional callback-based programming. By leveraging lightweight fibers, the library enables cooperative multitasking that maintains responsiveness during heavy data processing workloads. The framework distinguishes itself through a structured concurrency model that organizes tasks into parent-child hierarchies. This appr

Curio is a Python library for structured concurrency and asynchronous network programming. It serves as a framework for handling thousands of simultaneous TCP connections using non-blocking sockets and high-throughput I/O. The library organizes asynchronous operations into a hierarchy of parent and child coroutines to ensure reliable termination and cleanup of dependent tasks. It provides a toolkit for coordinating these concurrent operations through the use of task groups and timeouts. The framework covers a broad range of concurrency management capabilities, including inter-task communicat

pysheeet is a technical reference library providing a curated collection of code snippets and implementation patterns for advanced Python development, system integration, and high-performance computing. It serves as a comprehensive guide for implementing low-level network programming, native C extensions, and asynchronous and concurrent programming. The project provides specialized frameworks for the development and deployment of large language models, including tools for distributed GPU inference and high-performance serving. It also includes detailed patterns for high-performance computing

This is an open-source, crowd-sourced wiki textbook that teaches Linux system programming in C. It covers the core operating system concepts of process management through the fork-exec-wait model, dynamic memory allocation using implicit free list heap allocators, inode-based file systems, inter-process communication via pipes and shared memory, POSIX threads with synchronization primitives, signal-based asynchronous notification, virtual memory with page table translation, and runtime diagnostics using Valgrind and GDB. The textbook distinguishes itself by providing practical, implementation

ReactPHP is an asynchronous runtime and event-driven I/O framework for PHP. It provides an environment for executing concurrent tasks through a central event loop implementation and reactor pattern, allowing applications to handle multiple operations without pausing the main execution thread. The project includes a specialized asynchronous socket library for TCP, UDP, and TLS communication, alongside a non-blocking HTTP server and client for streaming web requests and responses. Its capability surface covers asynchronous control flow via promises and fibers, non-blocking network connectivity

libco is a C++ coroutine library and user-space task orchestrator designed for cooperative multitasking and high-concurrency execution. It functions as a high-concurrency network framework and a synchronous-to-asynchronous wrapper that allows blocking system calls and socket functions to run asynchronously without modifying existing business logic. The project utilizes a specialized stack-copying context switching model to support millions of simultaneous TCP connections on a single machine. It includes a high-performance time wheel scheduler for managing asynchronous background jobs and dela

Swoole is a coroutine-based concurrency library and IO framework for PHP. It provides a system for building high-performance network servers and applications by bringing asynchronous, event-driven, and coroutine-based concurrency to the PHP runtime. The project distinguishes itself by implementing user-space coroutine scheduling and non-blocking IO interception, which transforms standard blocking network and file operations into asynchronous actions. It further enables high-speed data exchange across multiple PHP processes through shared memory management and specialized data structures. The

Sanic is a Python ASGI web framework and asynchronous HTTP server. It is designed to build high-performance web applications and servers that handle concurrent requests using non-blocking logic. The framework implements the Asynchronous Server Gateway Interface standard, allowing applications to be deployed across various ASGI-compatible servers. It utilizes an asyncio-based event loop and integrates a Cython-based runtime wrapper around libuv to manage I/O operations. The system manages traffic through route-based request dispatching and a middleware-based request pipeline. These components

Asio is a C++ library for performing network and low-level I/O operations using a consistent asynchronous model that avoids blocking program execution. It provides a portable, cross-platform interface for network socket communication across different operating systems, and manages multiple asynchronous operations without requiring explicit thread management or locking. The library implements a proactor-based asynchronous model where operations post completion handlers to a queue for later execution, and wraps operating system I/O multiplexing mechanisms like epoll, kqueue, IOCP, and select in

Tornado is a Python web framework and asynchronous networking library used to build scalable web applications and high-performance servers. It provides a non-blocking HTTP server capable of handling thousands of simultaneous connections. The project functions as a WebSocket server framework, enabling real-time bidirectional communication and persistent connections between clients and servers. It supports the implementation of custom networking protocols and high-performance networking services beyond standard HTTP. Its capabilities cover asynchronous web application development, concurrent A

Swift NIO is a low-level, event-driven network framework for the Swift language. It serves as an asynchronous network protocol stack and I/O library designed to build high-performance network servers and clients that handle thousands of simultaneous connections. The framework functions as a high-concurrency network engine that dispatches events across multiple CPU cores. It enables the implementation of custom network protocols by processing raw bytes through a sequence of reusable data transformation handlers. The system provides capabilities for non-blocking I/O multiplexing, asynchronous

Muduo is a C++11 event-driven network library and framework designed for building high-concurrency Linux servers. It provides a toolkit for implementing scalable network services and socket communication using non-blocking I/O and asynchronous event processing. The framework implements a multi-threaded TCP server architecture that distributes connection handling across multiple CPU threads to maximize server throughput. This is achieved through a one-loop-per-thread model and a reactor pattern implementation, which dispatch network events from a central demultiplexer to registered handler fun

EventMachine is a reactor-pattern network framework for Ruby that provides an asynchronous I/O library for performing non-blocking network and file operations. It functions as a network server framework used to build scalable TCP and UDP servers and clients that process multiple simultaneous requests. The framework implements a concurrency model that dispatches network events to registered handlers using a single-threaded event loop. This approach allows for the management of high-concurrency network connections without the overhead of multi-threaded programming. The library covers the devel

cppcoro is a C++ coroutine library and concurrency toolkit providing primitives for asynchronous tasks, lazy generators, and non-blocking execution. It functions as an asynchronous I/O framework for managing network sockets and file operations through an event loop. The library features a work-stealing thread pool for distributing tasks across multiple cores and a set of async generators for producing lazy sequences of values both synchronously and asynchronously. It includes a concurrency toolkit with async mutexes, latches, and shared tasks to coordinate multi-threaded execution. Its capab

Kotlinx.coroutines is a library for managing non-blocking background tasks and structured concurrency within the Kotlin programming language. It provides a framework for executing concurrent operations and synchronizing shared state, replacing traditional thread management and complex callback chains with lightweight primitives. The library utilizes a structured concurrency hierarchy to organize hierarchical background tasks, ensuring that lifecycle management, cancellation, and timeout handling propagate automatically to prevent resource leaks. It employs continuation-passing style transform

Netpoll is an event-driven network framework and non-blocking I/O library designed to manage concurrent TCP and Unix domain socket connections. It utilizes a non-blocking event loop to monitor file descriptors and trigger callbacks for read and write events, serving as a high-performance socket manager and TCP network poller. The framework optimizes throughput across CPU cores by distributing incoming network connections across multiple pollers. It implements zero-copy networking primitives, using linked buffers and specialized memory management to read and write data while minimizing memory

f-stack is a kernel-bypass framework and user-space TCP/IP stack designed to increase packet processing speeds and overall throughput. It utilizes DPDK to route network traffic directly to user space and integrates a transplanted FreeBSD network stack to handle transport and network layer protocols outside of the host operating system. The project provides a socket API compatibility layer that allows standard network applications to run on a high-performance backend without requiring code changes. It also features a coroutine-based network API and micro-threading interface to manage asynchron

async-std is a Rust asynchronous runtime and non-blocking I/O library. It serves as an asynchronous standard library, providing a set of alternatives to the core Rust library for managing concurrent tasks, networking, and file system access. The project implements a standard-library-mirrored API, offering asynchronous versions of existing synchronous types to maintain a familiar interface. This approach allows for asynchronous Rust development using an interface that reflects the ergonomics of the language's standard library. The runtime includes a task executor for scheduling and executing

Crystal is a statically typed, compiled programming language designed for high performance and memory safety. It leverages an LLVM-based compiler to translate source code into optimized machine-executable binaries, while its type-inference-based static analysis enforces strict safety rules during the build process. The language distinguishes itself through a fiber-based concurrent runtime that manages lightweight execution units for asynchronous input and output without blocking the main process. It also features a powerful compile-time macro system that allows for the inspection and transfor

Seastar is a C++ server application framework and asynchronous programming library designed for building high-performance, shared-nothing server applications. It functions as a high-performance I/O engine providing direct disk and network access through a shared-nothing framework that partitions data and execution across CPU cores. The framework distinguishes itself through a thread-per-core architecture that eliminates locking and resource contention by assigning one execution thread to each physical CPU core. It implements a userspace TCP/IP stack and kernel-bypass techniques, integrating w

uvloop is a high-performance replacement for the standard Python event loop. It functions as a drop-in substitute designed to accelerate asynchronous networking tasks and reduce latency in event-driven software systems. The project achieves its performance characteristics by utilizing a Cython-based extension module that wraps the libuv C library. By leveraging low-level system calls for event-driven input and output multiplexing, it manages concurrent network requests and subprocess execution with minimal overhead. The implementation supports scalable backend service development by handling

Fasthttp is a high-performance networking framework for Go, designed to maximize throughput and minimize memory overhead in demanding web applications. It functions as a specialized HTTP server and client library that prioritizes efficient resource management, allowing developers to build scalable services capable of handling massive concurrent traffic with minimal garbage collection pressure. The library distinguishes itself through a focus on zero-allocation processing and low-level optimization. It achieves this by recycling temporary request and response objects through managed pools and

High level asynchronous concurrency and networking framework that works on top of either Trio or asyncio

Torch7 is a scientific computing environment and tensor computation library used for deep learning research and numerical analysis. It functions as a Lua-based framework for training neural networks and learning agents, providing a toolkit for implementing architectures and training through reinforcement learning algorithms. The project is distinguished by its tight integration with C, utilizing a binding layer to map high-level scripting to low-level C structures for direct memory access. It supports hardware-accelerated computation by offloading linear algebra and convolution operations to