Browse free open source Communications software and projects for Server Operating Systems and Linux below. Use the toggles on the left to filter open source Communications software by OS, license, language, programming language, and project status.
Anti-Spam SMTP Proxy Server implements multiple spam filters
You can message and share files inside your intranet without a server.
A universal instant messaging (IM) program
A free course management system (CMS) to create online learning sites
Development toolkit for Web Services and XML data bindings for C & C++
Fast Bayesian spam filter along lines suggested by Paul Graham
The most affordable CRM system according to Capterra
A fast cross-platform FTP client
MSN compatible messenger application
A P2P filesharing client which connects to the Gnutella network.
Transfer disks and disk images between the Apple II and the real world
A lightweight, high-performance Internet Relay Chat server
Multiplatform Ham Radio APRS and Mapping Program