Mattermost Desktop application for Windows, Mac and Linux
An alternative Discord client with voice support made with C++ and GTK
A patched version of discord, with bot login support
The first messaging platform operating without user identifiers
Java wrapper for the popular chat & VOIP service
Mumble is an open-source, low-latency, high quality voice chat
A New Kind of Instant Messaging
A reference implementation of the SimpleX Messaging Protocol
Berty is a secure peer-to-peer messaging app
The extensible chat client
The very last word in instant messaging
Discord Messaging Panel that allows you to message inside of a bot
A Windows client for the Direct Connect networks
VICIdial Contact Center Suite
Youtube deletes your comments?
Secured blockchain group messaging
OTP-Chat (client / server) YOUR PC is both client and server!
A free client for sb0t an other servers in the Ares Network
ChatSecure is a free and open source encrypted chat client for iOS
Legacy mobile Rocket.Chat client in Kotlin for Android
Open-source XMPP client for Android
NetPCLinker (p2p) (Chat, FilesTransfer, Phone, Share)