Astlinux is a bundled distribution of the Asterisk open source iPBX private branch exchange (PBX) software and a Linux operating system. Originally developed by Mark Spencer at Digium, Asterisk is the leading open source software in the telephony/VoIP space. Asterisk excels at combining traditional TDM telephony capability - provided through hardware from Digium and others - with VOIP services. These include call routing, media gateway, media server and SIP signaling capabilities.