Yukon is a set of libraries and applications that are designed to capture realtime videos of OpenGL applications (games). The original design idea is based on Anandtech's FrameGetter, but was extended to suit todays high-performance computers.
CamStudio is able to record all screen and audio activity on your computer and create industry-standard AVI video files and using its built-in SWF Producer can turn those AVIs into lean, mean, bandwidth-friendly Streaming Flash videos (SWFs)
Taksi is a utility that allows you to take screenshots and record video clips of your favourite games and other 3D-graphics applications. Inspired by Fraps (www.fraps.com), Taksi aims to provide an open source alternative to that great tool.
Taksi can support live video compression with any VFW video codec your system has installed (i.e. XVid, DivX, MS Mpeg4, etc).