PS_View is a PostScript and PDF previewer. It is multiplatform (Windows, Linux and Mac OS X), GUI program based on the Ghostscript engine. Key features include huge magnification, fast viewing of large documents, exact measuring, and restart.
3DMLW is a 3D engine and markup language based on XML that is capable of running in common web browsers. It supports .3ds, .obj, .an8 (Anim8or) models and experimental .blend (Blender) support, .tga, .jpg and .png textures and .ogg sound.