- GnuGk



- 115 downloads
The GNU OpenH323 Gatekeeper is a rich H.323 gatekeeper including radius and database support.
- Elastix



- 279 downloads
Elastix is a user-friendly open source telephony calling tools for Asterisk PBX.
- Mumble

- 206 downloads
Geared for gamers, Mumble is a voice linking telephony system with multiple features suitable for game play.
- TrixBox CE



- 144 downloads
TrixBox CE is an internet telephony program based on Asterisk PBX.
- Skype



- 115 downloads
Skype is one of the most popular free telephony applications available.