“…MRToolkit (Shaw et al, 1992) C CAVELib (VRCO, 2003) C VB2 (Gobbetti et al, 1993) Eiffel Performer (SGI, 2003) C + + Avocado (Tramberend, 1999) C++, Lightning (Blach et al, 1998) C++, WTK (Sense8, 2000) C + + MASSIVE-2 (Benford et al, 1997) C++ Alice (University of Virginia, 1999) Phyton VRJuggler (Bierbaum et al, 2001) C++ X3D (Web3D Consortium, 2003 XML CONTIGRA (Dachselt et al, 2002) XML HyNet (Massink et al, 1999) Petri Nets PMIW (Jacob et al, 1999) Dataflows and State Machines VRPN (Russell et al, 2001) C + + InTml XML A darker gray means a better coverage than a lighter one, from the viewpoint of a developer.…”