In the field of VoIP networking, the Open Phone Abstraction Library (OPAL) continues the open-source openh323 project to support a wide range of commonly used protocols used to send voice, video and fax data over IP networks rather than being tied to the H.323 protocol.
OPAL implements a wide range of Voice over IP (VoIP) protocols for voice, video and fax data over IP networks.
It is written in C++ and released under the Mozilla Public Licence.
OPAL utilises the PTLib portable library that allows OPAL to run on a variety of platforms including Unix/Linux/BSD, MacOSX, Windows, Windows mobile and embedded systems.
OPAL is used by the open source Video Conferencing Program Ekiga (formerly GnomeMeeting).