Socket.io is a JavaScript library that enables real-time, bi-directional communication between web clients and servers. It is based on the WebSocket protocol and enables applications to function with low latency and high throughput. Socket.io is used to create real-time applications, such as chat applications, real-time collaborative applications, multiplayer games, and even IoT applications. It is a great tool for developers since it allows them to quickly create real-time applications without the need for complex coding and configuration. Socket.io also supports different transport layers (such as WebSockets, Long Polling, and AJAX) to ensure that your application is reliable and can handle high amounts of traffic. Socket.io is an open source project, meaning that it is free to use and is constantly being improved by the community.
Discontinued Looks dead.
Discontinued The project is no longer maintained. The latest version, 1.2.0, released in August 2016, can still be downloaded from GitHub.
It is a file sharing system that is totally different from socket.io.