asterisk is open source PBX software designed for the Linux
asterisk eliminates the need of buying hundreds or even thousands of dollars worth of dedicated PBX hardware.
Aside from Linux, asterisk also runs on various other operating systems, including: BSD, OS X, and now the Windows
operating system using "AstWind" package.
Admin: We need a PBX for our organization, but we're kinda low on cash to buy expensive PBX hardware...
Assistant: No problem! Use asterisk, the open source Linux PBX.
Admin: I feel so stupid...