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OpenSER - http://openser.org/
A branch of the SIP Express Router project, offering an open-source SIP server. |
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3CX - http://www.3cx.com
Developers of IP PBX software for Windows. |
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Applied Voice & Speech Technologies, Inc. (AVST) - http://www.avst.com
Applied Voice and Speech Technologies, Inc. (AVST) offers SIP integrations to its flagship CallXpress unified communications platform. |
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Interactive Intelligence, Inc. - http://www.inin.com/sipproxy
Developers of a proxy server. Site contains downloads, documentation and a forum. |
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LignUp Corp - http://www.lignup.com/
Applications developer. Products include software PBX's for enterprise and service providers. |