Homer Conferencing (short: Homer) is a free SIP softphone with advanced audio and video support. The software is available for Windows, Linux and OS X. Homer was developed as tool for video conferences and as streaming platform. The basic functions of Homer are separated into 4 application areas: video conferencing, streaming, recording, screencasting.
More details can be found here: http://www.homer-conferencing.com.
Parts of the software were integrated into the "Forwarding on Gates" software FoGSiEm. They can be found as video plugins of FoGSiEm.