Open Source Android WebSocket Libraries

Mongoose is a networking library for C/C++. It implements event-driven non-blocking APIs for TCP, UDP, HTTP, WebSocket, MQTT. It is designed for connecting devices and bringing them online. On the market since 2004, used by vast number of open source and commercial products - it even runs on the International Space Station! Mongoose makes embedded network programming fast, robust, and easy. Cross-platform, works on Linux/UNIX, MacOS, Windows, Android, FreeRTOS, etc. Supported embedded architectures: ESP32, NRF52, STM32, NXP, and more. Built-in protocols: plain TCP/UDP, HTTP, MQTT, Websocket. SSL/TLS support: mbedTLS, OpenSSL or custom (via API). Used to solve a wide range of business needs, like implementing Web UI interface on devices, RESTful API services, telemetry data exchange, remote control for a product, remote software updates, remote monitoring, and others.

socket.io is a JavaScript library that allows for realtime, bi-directional communication between web clients and servers. It is composed of two parts: a Node.js server and a JavaScript client library that runs in the browser. socket.io is focused on both reliability and speed, delivering an immensely powerful, fast and yet easy to use realtime engine that’s used by just about everyone: from Microsoft Office and Zendesk to hackathon winners and small startups. It’s considered one of the most depended-upon npm modules, and works on every platform, browser or device.

Racoon is a fast, fully customizable web framework for Rust focusing on simplicity.