Chat & Messaging (Third-party Clients): open-source projects that exist because someone reverse engineered a closed product, sorted by GitHub stars.
Slack client for the terminal
Unofficial Microsoft Teams desktop client for Linux (Electron)
Mod for the Discord Android app with plugin support
Unofficial DingTalk desktop client for Windows, Linux and macOS built on the web version
Fully native Discord client for macOS built in Swift
WeeChat script for Slack with threads, reactions and read-marker sync
CLI/TUI client for Slack
Fast native WhatsApp client in Rust and egui built on a reverse-engineered protocol library
Alternative Discord client in C++/GTK3 with voice support
Terminal messaging client for Telegram, WhatsApp (whatsmeow) and Signal
Client modification for the Discord mobile app
Discord terminal client (archived)
Mod for Discord's mobile apps (React Native)
Slack client for Emacs
Lightweight Discord client mod focused on simplicity and performance
Command-line WhatsApp client built on reverse-engineered WhatsApp Web protocol
Feature-rich Discord TUI client
Configurable, privacy-minded third-party Discord client
Console Facebook Messenger client using reverse-engineered web endpoints
Discord client mod designed to survive Discord client updates
GTK3 Discord client in Go (predecessor of Dissent)
Unofficial Gitter.im chat client for iOS and Android (React Native)
Extensible iMessage chat bot for macOS written in Swift
Terminal Discord client in Python
Ultra-lightweight native Discord client for vintage and modern Mac OS
Native Windows Live Messenger 2009-themed Discord client
Unofficial Electron desktop client for ProtonMail
Discord client for Java ME (MIDP) feature phones
Command-line messaging for Facebook Messenger
Fast Slack TUI client
Native Discord client for modern Macs written in Swift
Open-source Discord client for Windows 10 and Windows Phone 10
Discord client for Windows and Xbox with voice chat support
Unofficial WhatsApp client for MeeGo/Harmattan built on yowsup
Discord client mod with webpack module patching and extensions
Native Discord client for Apple platforms
Connect to Mattermost or Slack using any IRC client
BitlBee plugin that exposes Discord to IRC clients
Facebook Messenger protocol plugin for BitlBee
Mac relay server that exposes iMessage to AirMessage Android/web clients
Lightweight Discord desktop client mod
Alternative Discord client with voice support in C++ and Qt 6 Widgets
Discord client powered by Node.js and Qt Widgets
iMessage client for classic Macintosh (System 2.0 to Mac OS 9.2.2)
Keyboard-driven terminal WhatsApp client (Ratatui + whatsmeow)
Discord client for TempleOS
Native Discord client for power users
Native Discord client in Python/Qt
Discord client in C++ and Qt
Lightweight native Discord client built with Qt
Terminal Discord client in Go (mirrored from GitLab)
Native macOS Discord client in Swift and SwiftUI
Discord client for the Nintendo 3DS
Discord TUI client written in Rust
Cross-platform Discord mobile client modification
rdircd: use Discord through any IRC client via the user gateway API
Self-hosted iMessage client
TUI-based client for Slack
Local-first Google Messages and WhatsApp inbox for Mac, web and MCP
Lightweight unofficial Discord client
Unofficial Discord client for KaiOS
Unofficial native WhatsApp client for Linux
Unofficial native LINE client for Linux using a linejs protocol sidecar
Unofficial Discord client for the Nintendo Switch
Unofficial WhatsApp client in Rust built on whatsapp-rust
Unofficial Discord client for the Nintendo Switch
Unofficial Discord client for FreeBSD
Unofficial Discord client for the PS Vita
Unofficial experimental QQ client for Nintendo Switch homebrew
Unofficial Discord client for QNX BlackBerry 10 devices
Unofficial GTK client for WhatsApp, built with Rust
Unofficial Discord client for Windows Mobile
Unofficial Discord client for KaiOS feature phones