SIPfoundry
SIPfoundry is a not-for-profit organization, whose mission is to promote and advance open-source software projects based on the Session Initiation Protocol (SIP). The community aims to support users, developers, and distributors of SIP-based products.
Founded in March 2004, SIPfoundry established close ties with the SIP Forum as well as the IETF. SIPfoundry actively promotes the standardization of SIP and interoperability of SIP products and solution across the industry through the SIP Forum Test Framework (SFTF).
SIPfoundry spawned the development of sipX, an open source SIP private branch exchange (PBX) for Linux. This project aims at commoditizing PBXs by offering a fully featured, standards-compliant, and easy-to-use SIP IP PBX for free as an open source solution. SIPfoundry would like SIP to become part of the Internet the same way HTTP, SMTP, and XML became ubiquitous and drove rapid adoption of new services across the Internet.