ThreeJS - A WebGL-based back end using the ThreeJS scene-graph library (currently: Release 69). The scene format is IGXC, the geometry format is OBJ.
X3DOM - A WebGL-based back end using the X3DOM scene-graph library (currently: Version 1.6.1). The scene format is X3D(OM), the geometry format is BinGeo.
Unity-3D - Commercial game development tool targeting multiple platforms. The scene format is IGXC (obsolete: EOX-GFX), the geometry format is OBJ. This back end has restricted support for interactive features, but provides the IG.Std interactors by an own implementation. Also, IG.GFX Mapping is not yet available.
FAPI/pCon - EasternGraphics application based on the FAPI kernel. The scene format is EOX-GFX, the geometry format is OBJ. This back end has no support for interactive features. Also, IG.GFX Mapping is not yet available.