A reference implementation of the SimpleX Messaging Protocol
Berty is a secure peer-to-peer messaging app
Distributed instant messaging system for developers
A universal instant messaging (IM) program
You can message and share files inside your intranet without a server.
Development toolkit for Web Services and XML data bindings for C & C++
PHP & MySQL based CMS with messenger
Chat Messenger. E-Mail-Client. Websearch. Filetransfer.
Smoke: Android Crypto Chat Messenger
Software per Call Center
IXSF Messenger is a java-based messenger
Open-source social network CMS and mobile apps.
Messaging app with client server architecture.
Internal communication software for business
Create chat bots for Facebook Messenger, Slack, Amazon Alexa, etc.
This Program Contains Many Useful Network Tools
MSN compatible messenger application
A small, reliable, local network messenger that doesn't need internet
Instant Messenger Application
A small (ish) messaging server for anything you can think of
simple yahoo messenger client