J-IM is a lightweight, high-performance, single-machine based on t-io developed in JAVA language. It supports hundreds of thousands to millions of online user IM. The main goal is to reduce the threshold of instant messaging and quickly create a low-cost access to online IM system. The extremely concise message format can realize the sending of messages between multi-end different protocols such as built-in (Http, Websocket, Tcp custom IM protocol), etc., and provides the message sending through the api interface of the http protocol without caring about what protocol the receiving end belongs to, a The message format does everything!