OpenSceneGraph 2.4 is available. This version adds geometry shaders, multiple render targets, support for terabyte scale terrain databases, writing to OpenFlight and much more.
Further information: OpenSceneGraph 2.4 press release
The OpenSceneGraph is an open source high performance 3D graphics toolkit, used by application developers in fields such as visual simulation, games, virtual reality, scientific visualization and modelling. Written entirely in Standard C++ and OpenGL it runs on all Windows platforms, OSX, GNU/Linux, IRIX, Solaris, HP-Ux, AIX and FreeBSD operating systems.