asterisk: Asterisk® (Open Source PBX!)
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asterisk: Asterisk is a complete  PBX in software. It  runs  on  Linux, BSD  and
asterisk: MacOSX and  provides  all  of the features you would expect from a PBX
asterisk: and more. Asterisk does  voice  over  IP  in  many  protocols, and can
asterisk: interoperate with almost all standards-based telephony equipment using
asterisk: relatively inexpensive hardware.
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