Open-source alternatives to Ratchet

libhv is a high-performance C/C++ network library and event-driven I/O framework used to build TCP, UDP, SSL, HTTP, WebSocket, and MQTT clients and servers. It provides a non-blocking event loop for managing network sockets, timers, and system signals across multiple threads. The project is distinguished by its integrated support for specialized network roles, including a full HTTP web server with RESTful routing and middleware, an MQTT messaging client for IoT communication, and the ability to implement SOCKS5 and HTTP proxies. It also features a reliable UDP implementation to ensure ordered

Quart is an asynchronous Python web framework that implements the ASGI specification. It is used to build high-performance HTTP and WebSocket services, JSON REST APIs, and web applications using async and await syntax for non-blocking request handling. The framework supports persistent bidirectional communication via WebSocket API servers and enables the proactive delivery of assets through HTTP server push. It also includes a template engine for rendering dynamic HTML web pages and supports incremental request and response streaming to manage large payloads. General capabilities cover reque

websockets is a Python library that provides both client and server implementations for the WebSocket protocol, enabling real-time, bidirectional communication between applications. At its core, it offers the fundamental primitives for establishing persistent connections, managing their lifecycles, and exchanging text or binary messages asynchronously using coroutines. The library distinguishes itself through comprehensive support for various messaging patterns, including broadcast messaging to all connected clients, targeted messaging to specific clients, and shared application state synchro

Kore is an event-driven web and WebSocket server framework designed for building high-performance web services and APIs in C or Python. It functions as a secure, concurrent application framework that utilizes non-blocking I/O and isolated worker processes to handle high-concurrency traffic. The project is distinguished by a security-first architecture that features OS-level process sandboxing, privilege separation, and the isolation of private encryption keys into dedicated processes. It enables zero-downtime deployments through dynamic module hot-reloading and provides automated TLS certific

PHP-Websockets is a network programming library that provides a persistent server implementation for handling bidirectional real-time communication. It functions as a framework for managing asynchronous data exchange between web clients and server-side application logic, enabling the development of responsive systems that react to incoming messages. The library facilitates the hosting of WebSocket servers by managing persistent connections and pushing live updates to users. It handles the technical requirements of the protocol, including the validation of upgrade requests through handshake ne

Melody is a WebSocket server framework designed to upgrade HTTP connections into bidirectional streams. It functions as a session manager and binary streaming library that facilitates real-time data exchange between a server and multiple remote clients. The project features a broadcast engine that optimizes multi-client transmissions through wire-representation caching. It includes a dedicated session management system for attaching custom state to persistent network connections and an upgrade handler that validates handshake headers. The framework covers broad capability areas including eve

This project is a Node.js WebSocket library that provides a high-performance client and server implementation for the WebSocket protocol. It functions as a transport layer for real-time bidirectional communication, supporting both UTF-8 strings and binary data transport through the use of TCP socket wrappers. The library enables the creation of WebSocket servers that manage full-duplex connections and broadcast messages to multiple clients, as well as WebSocket clients that establish persistent links to remote servers. It handles the protocol upgrade process via TCP-based handshake negotiatio

PartyKit is a serverless WebSocket backend platform for building real-time multiplayer applications. It provides a globally distributed edge computing runtime that runs stateful server code close to users, with automatic scaling and hibernation for idle rooms. The platform handles WebSocket connections, HTTP requests, and durable storage without requiring infrastructure management, and includes a client and server SDK with hooks, storage, and Yjs integration for building collaborative features. The platform distinguishes itself through per-room isolation using Durable Objects, where each uniq

Elysia is a high-performance TypeScript web framework designed for building type-safe backend services. It provides a modular, plugin-based architecture that allows developers to compose server logic, middleware, and validation schemas into scalable application instances. By leveraging native web standards, the framework ensures portability across diverse JavaScript runtimes, including Node.js, Deno, and various edge computing environments. The framework distinguishes itself through its focus on end-to-end type safety, automatically synchronizing request and response definitions between the s

NanoHTTPD is a lightweight, embeddable HTTP server for Java applications. It allows developers to integrate web server capabilities directly into a Java project to handle incoming requests without requiring a standalone installation. The project provides specialized implementations for an HTTPS web server, a WebSocket server for bidirectional real-time communication, and a static file web server. These capabilities enable secure network traffic through SSL certificates and the delivery of local files with automatic MIME type detection. The server includes systems for request routing and hand

Java-WebSocket is a collection of classes for implementing WebSocket clients and servers using pure Java. It provides a framework for hosting servers that manage connections via event-driven subclasses and tools for establishing client connections to remote servers. The library includes a secure communication tool for encrypting traffic using the WSS protocol and a compression library that uses per-message deflate extensions to reduce transmitted data size. It supports the configuration of cipher suites to limit encryption protocols and ensure compatible communication. The project enables bi

Uvicorn is an ASGI web application host designed for asynchronous Python web development. It serves applications through a standardized asynchronous server gateway interface to handle non-blocking network traffic and high-concurrency requests. The server manages both HTTP and WebSocket traffic, including the handshaking process required to establish persistent, full-duplex communication channels for real-time data exchange. For development workflows, the project includes a hot-reload mechanism that monitors the filesystem for source code changes and automatically restarts the server process.

Laf is a serverless backend platform that provides an integrated environment for cloud functions, a document database, and file storage. It serves as a complete infrastructure for developing and deploying backend logic, data persistence, and real-time communication without the need for manual server management. The platform features a browser-based IDE that allows developers to write, test, and deploy serverless functions directly within a web editor, removing the requirement for local environment setup. It also includes a WebSocket communication platform for maintaining persistent bidirectio

Vibora is an asynchronous Python web framework and built-in HTTP server designed for building high-performance web applications. It utilizes an asynchronous event loop and coroutines to process network requests and serve responses without requiring external server wrappers. The project features a high-performance asynchronous schema validator for request integrity, a non-blocking template engine with support for hot-reloading, and a WebSocket communication server for bidirectional real-time data exchange. The framework covers a broad range of capabilities, including modular route management

This project is an event-driven PHP application server and HTTP server bridge that allows Laravel applications to run on a persistent engine. By keeping the application in memory, it eliminates the boot overhead typically required for every individual request to increase request speeds. The server includes an application state sandbox that isolates the application container between requests to prevent data leakage and state pollution. It also features a shared memory data store for retrieving information across multiple worker processes and provides a WebSocket server implementation for persi

This is a minimal WebSocket library for Go designed for bidirectional real-time communication. It serves as a network protocol implementation for managing handshakes, frame masking, and control signals to enable the exchange of text and binary messages over persistent connections. The library distinguishes itself by providing a connectivity layer that wraps browser WebSocket APIs for applications compiled to WebAssembly. It also functions as data compression middleware, utilizing deflate compression to reduce bandwidth usage for transmitted messages. The project covers a broad range of netwo

uWebSockets is a C++ networking framework that serves as a high-performance WebSocket server library, HTTP web server, and pub-sub messaging system. It provides the infrastructure necessary to handle standard web requests and maintain low-latency, bidirectional connections between clients and servers. The framework is distinguished by its use of template meta-programming for compile-time optimization and zero-copy buffer management to minimize memory latency. It utilizes a backend-agnostic event loop and static route resolution to process network traffic with minimal runtime overhead. The pr

This framework is a distributed systems runtime designed for building fault-tolerant, message-driven microservices and high-performance network applications in PHP. It provides an asynchronous execution environment that utilizes event-loop-based concurrency and promise-based task orchestration to manage high-concurrency workloads without blocking execution threads. The platform distinguishes itself through a unified execution abstraction that manages multi-process and multi-threaded components as isolated, supervised containers. By employing an actor-model approach to process supervision, the

This project is a comprehensive library of reference implementations and patterns for building web applications using the Go Fiber framework. It provides curated templates and implementation guides for creating REST APIs, web servers, and structured backend services. The repository serves as a practical resource for applying architectural patterns, including Clean and Hexagonal architectures, as well as port-and-adapter decoupling. It offers detailed examples for integrating common web features such as OAuth2 authentication, JWT verification, WebSockets for real-time communication, and server

Evio is a high-performance networking library for Go that provides a non-blocking socket framework. It utilizes an event loop to process TCP, UDP, and Unix domain socket traffic through a low-level asynchronous protocol interface. The project functions as a multi-core network load balancer, distributing connections across multiple CPU cores using round-robin or least-connections strategies. It supports socket reuse, allowing multiple sockets on a single host to bind to the same port. The library covers a broad range of socket management and packet processing capabilities, including multi-pro

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

This Go library provides low-level components for implementing high-performance WebSocket connections. It focuses on minimal memory allocations and efficient data throughput via a dedicated frame processor, an HTTP connection upgrader, and a compression layer. The project distinguishes itself through the use of zero-allocation buffer reuse to reduce garbage collection pressure. It operates directly on raw network bytes for frame parsing and manages the lifecycle of connections through state-based tracking. The library covers core network protocol capabilities including the transformation of

This library provides a framework for building event-driven, non-blocking network applications in PHP. It enables the development of asynchronous TCP and TLS servers and clients that manage multiple concurrent connections without stalling the main execution thread. By utilizing an event-loop architecture, the library handles network operations and data exchange through asynchronous streams, ensuring that the application remains responsive during high-throughput tasks. The project distinguishes itself through its integration with operating system primitives, such as raw file descriptors and Un

ESPAsyncWebServer is an asynchronous web server designed for ESP32 and ESP8266 microcontrollers. It enables these devices to host websites and APIs to provide embedded device interfaces for hardware control and data display. The server utilizes non-blocking HTTP handling to process multiple concurrent network connections. This allows the device to manage web requests without pausing other background tasks or sensor readings. The implementation relies on asynchronous socket operations, event-loop request handling, and buffer-based stream parsing. It integrates directly with the network layer

shadowsocks-libev is an event-driven network daemon that provides an encrypted SOCKS5 proxy. It functions as a lightweight proxy server using a non-blocking event loop to route TCP and UDP traffic through encrypted tunnels to bypass network restrictions. The project implements a transparent proxy gateway capable of intercepting outbound packets at the network layer, allowing system traffic to be redirected through the encrypted tunnel without per-application configuration. It also includes a daemon process manager to control multiple proxy server instances as child processes via local communi

Oak is a cross-runtime HTTP middleware framework and web server designed to operate across Deno, Node.js, Bun, and Cloudflare Workers. It provides a unified system for building APIs and web servers using a sequential chain of middleware functions and a hierarchical routing engine that maps URL paths to handlers via a nested tree structure. The framework includes a runtime-agnostic serverless adapter that translates diverse cloud provider events into a standard request and response interface. It also features a dedicated WebSocket server implementation for bidirectional real-time communication

Pyppeteer is a Python library for controlling Chromium-based browsers using the Chrome DevTools Protocol. It functions as a headless browser automation tool, allowing for the programmatic navigation of web pages and the extraction of data from dynamic websites. The project provides low-level browser control through direct communication with the Chrome DevTools Protocol, enabling the interception and modification of network traffic. It differentiates itself by offering specialized performance profiling capabilities, including the measurement of JavaScript and CSS code coverage and the capture