Mark Spencer, the creator of Asterisk, has created numerous popular open-source tools including GAIM, the open-source AOL Instant Messaging client that is arguably the most popular IM client for Linux, l2tpd, the L2TP tunneling protocol daemon, and the Cheops Network User Interface, a network service manager. In 1999, Mark had a problem though. He wanted to buy a PBX for his company so they could have voice mail, call other offices without paying for the telephone call, and do all the other things one expects from a PBX system.