Freeware open source
WebCamStudio (GNU/Linux) allows to create a virtual web-cam, that can be used:
- to broadcast (stream) your desktop (with your webcam)
- as a virtual web-cam (useful when your web cam is not supported by flash on a web-site)
- to add video effect to your web-cam
WebcamStudio is compatible with Flash sites.
When you use a web-site that allows to broadcast live videos (like UStream, LiveStream) select the "vloopback module" option.