Telegram Desktop messaging app
Home to the Signal Protocol and other cryptographic primitives
A free (libre) open source, mobile OS for Ethereum
A Decentralized, Onion Routed, Private Messenger
A New Kind of Instant Messaging
LXMF client for Android, Linux and macOS to communicate with people
Private messenger for Windows, Mac, and Linux
Modern XMPP ("Jabber") Chat Client using GTK/Vala
A free and open source instant messaging and VoIP platform
Desktop Telegram client with good customization and Ghost mode.
Saves Discord chat logs to a file
Elegant Facebook Messenger desktop app
The first messaging platform operating without user identifiers
WhatsApp library for NodeJS that connects through the browser app
In-memory message queue with an Amazon SQS-compatible interface
Open source machine learning framework to automate text conversations
Desktop client for Facebook Messenger
A Tox-based instant messaging and video chat client
Franz is a free messaging app for services like WhatsApp, Slack, etc,
Telegraph is a Laravel package for fluently interacting with Telegram
A reference implementation of the SimpleX Messaging Protocol
Distributed instant messaging system for developers
Python chatbot framework with Natural Language Understanding
You can message and share files inside your intranet without a server.
A universal instant messaging (IM) program