3CX Phone System is a Debian-based distribution designed to run a complete unified communications platform. The 3CX client, included in the distribution, can also be installed separately on most hardware as well as the cloud. It provides a complete open standards-based IP PBX and phone system that works with popular SIP trunks and IP phones. 3CX joined the list October 31, 2016 with the release of a Linux beta. 3CX 8.6.0 RC was released December 13, 2016. 3CX 15.5 was released October 2017.