Wikipedia
AskoziaPBX is an open source telephone system (or " PBX") firmware. It is a fork of the m0n0wall project and uses the Asterisk private branch exchange (PBX) software to realize all telephony functions.
AskoziaPBX is released under a restricted BSD license. It permits all forms of Open Source modification and distribution but requires licensing if AskoziaPBX is to be sold on commercial products.
Since 2.1 version, it has been released under Commercial license only. Askozia also provides a "diet" version for testing. It has the full feature set, but is limited to two simultaneous calls.
Originally based on FreeBSD, AskoziaPBX was modified to run on Linux creating a new Linux distribution for this purpose. Running on Linux it has also been expanded to run on Blackfin and PowerPC CPU architectures in addition to the original x86.