General IM UI components. Android/iOS/RectNative ready. 通用 IM 聊天 UI 组件，已经同时支持 Android/iOS/RN。

Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots

Open source, native iOS Messenger, with audio/video calls and realtime chat conversations (full offline support).

Conversations is an open source XMPP/Jabber client for Android

Jitsi is an audio/video and chat communicator that supports protocols such as SIP, XMPP/Jabber, AIM/ICQ, IRC and many other useful features.

📱 Wire for iOS (iPhone and iPad)

免费IM系统，IM即时通信消息系统(含一对一文字聊天，群聊，聊天室)，免费一对一voip实时通话，录屏，webrtc服务端，免费直播连麦，互动直播，视频直播，RTSP拉流，RTMP推流，语音对讲，免费在线会议，视频会议等服务端程序，支持物联网平台，✨万水千山总是情，来个star行不行✨

golang im server

Chat SDK Android - Open Source Mobile Messenger

Movim - Decentralized social platform

Chat SDK iOS - Open Source Mobile Messenger

YiChat-基于tigase的独立IM系统

Routr: Next-generation SIP Server

An IRC to other chat networks gateway 🐝

coyim - a safe and secure chat client

IM server based on netty. Provides a client jar. Integrate with your own login system.基于netty实现的IM服务端,提供客户端jar包,可集成自己的登录系统

XMPP client

Miranda NG: Next Generation of Miranda IM

Loqui IM allows you to use all your chat accounts in just one FirefoxOS or Ubuntu Touch app.

Delta Chat Rust Core library, used by Android/iOS/desktop apps and bindings

🚀构建分布式即时聊天、消息推送系统。 Building distributed instant messaging, push notification systems.

Tinode chat client application for Android

基于网易云信 IM SDK for Android，界面仿造QQ和微信，打造的一款简单的即时通讯 APP，目前可实现好友添加，个人资料修改，基础聊天功能（包括文字，表情，语音，视频，图片和位置信息发送接收功能），Based on Netease cloud letter IM SDK for Android, the interface mimics QQ and WeChat, to create a simple instant messaging APP, which can be realized by adding friends, modifying personal information, basic chatting functions (including text, emoticons, voice, video, Location information send and receive function).

Tinode web chat using React

android client

📶即时消息推送服务(即时通讯)，基于Netty+protobuf-- Instant Messaging push service based on Netty+protobuf