SIP Websites

Developers of IP PBX software for Windows.

Applied Voice and Speech Technologies, Inc. (AVST) offers SIP integrations to its flagship CallXpress unified communications platform.

Commercial software development company that produces PBX, router, proxy and application server software.

VoIP telephony server software manufacturer. Includes product information, free download trials, and details of the support available.

A cross-platform SIP server running on Windows and Ubuntu. Detailed documentation.

SIP based VoIP and instant messaging software for office needs.

Products include SIP server and VoIP-server with SIP and H.323 protocols support.

A stateless primitive SIP server in Perl for education.

A branch of the SIP Express Router project, offering an open-source SIP server.