Syphon is an open source Mac OS X technology that allows applications to share frames - full frame rate video or stills - with one another in realtime.
openRTSP is a command-line program that can be used to open, stream, receive, and (optionally) record media streams that are specified by a RTSP URL - i.e., an URL that begins with rtsp://
Audio/Visuals Tools for VJ's: FreeFrame, After Effects, WinAmp, and Video Streaming
Video clone split cam capture driver software