Asterisk
URL = http://www.asterisk.org/
= open PBX platform
Description
"Asterisk is a complete IP PBX in software. It runs on a wide variety of operating systems including Linux, Mac OS X, OpenBSD, FreeBSD and Sun Solaris and provides all of the features you would expect from a PBX including many advanced features that are often associated with high end (and high cost) proprietary PBXs. Asterisk® supports Voice over IP in many protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware.
Asterisk is released as open source under the GNU General Public License (GPL), and it is available for download free of charge. Asterisk is the most popular open source software available, with the Asterisk Community being the top influencer in VoIP.
Asterisk was created by Mark Spencer of Digium, Inc in 1999. Code has been contributed from open source coders around the world, and testing and bug-patches from the community have provided invaluable aid to the development of this software." (http://www.asterisk.org/about)
Status Report on Open Source adoptiion of VoIP in 2007=
"Asterisk-based VoIP applications and appliances have been downloaded by business phone system Stay on budget with simple to install HP server technology. users more than 4.4 million times, implying millions of users, according to Digium, whose founder, Mark Spencer, started what has grown to become Asterisk's globe-spanning open source project collaboration.
Following his founding of Linux Support Services in 1999 while a computer engineering student at Auburn University, Spencer turned his attention to PBXs (private branch exchanges). He got the open source Asterisk ball rolling using his Linux-based PC and knowledge of the C programming language to write his own digital PBX. Shortly thereafter, he founded Digium.
The rest, as they say, is history. The Asterisk-based open source PBX project drew contributions from open source developers worldwide, who have formed the open source Asterisk community.
Today, a relatively small but expanding group of young independent digital telecommunications software providers are joining with some larger, established firms to support Asterisk-based digital PBXs, particularly for the small and medium-sized business sector.
Like many early open source community pioneers, "Spencer strongly believes that every technology he creates should be given back to the community. This is why Asterisk is fully open source," Bill Miller, Digium's vice president of product management and marketing, told LinuxInsider.
"This model has allowed Asterisk to remain available free of charge, while it has become as robust as the leading and most expensive PBXs," Miller said. "The Asterisk community includes ambassadors and contributors from every corner of the globe. Major corporations even have teams of developers building Asterisk-based products and solutions." (http://www.linuxinsider.com/story/9KMRNBq3L8g6gz/Open-Source-Changing-Models-Changing-Mindsets-Part-1.xhtml)