In addition to anaglyph stereo active stereo is supported in TerraStereo.
Select File -> Settings -> Stereomode -> OpenGL
Note: Active stereo requires nVidia Quadro board (Quad Buffered OpenGL). For instance, GeForce boards will not work.
We are just now testing AMD based quad buffered boards and support for those will come within this year.
For more information on hardware and GPU recommendations please see the TerraStereo product page.