Open source PBX software that runs under Linux and ... Supporting traditional telephony (TDM) as well as voice over IP (VoIP), Asterisk is written in C and uses the Unix standard POSIX programming ...

Asterisk is the heavyweight of open-source PBX ... Headquarters: Los Angeles Fonality's trixbox Pro, the business version of its IP-PBX software trixbox, comes in four editions: Pro Standard ...