SIPfoundry is a non-profit organization that develops open-source telephone software projects based on the Session Initiation Protocol(SIP).
Founded in 2004,[1] SIPfoundry established ties with the SIP Forum.[2] SIPfoundry promotes the standardization of SIP and interoperability of SIP products through the SIP Forum Test Framework (SFTF).
SIPfoundry spawned the development of sipXecs, an open source and standards-compliant SIP private branch exchange (PBX) for Linux.