Just about everything. First I can freeview both parallel and cross, I have most variants of anaglyph glasses (red/cyan, red/green, Color Code, etc.), slide viewers (both Realist format and medium format), Holmes viewers, lorgnettes, Loreo, Pokescope, Viewmaster, and I project both slide film and digital images using passive polarization. What I don't have is shutter glasses for monitors or 3DTV's. Is there a particular question about 3D I can answer for you?