STL Viewers and STL repair
Virtually all Rapid Prototyping and 3D Printing machines use the STL file format for input.
Below follows a list of programs to view and also sometimes convert, repair, edit, scale or cut STL files.
To learn how to export a STL file from your CAD program see here.
Open Source STL Viewers
GLC_Player is an Open Source software used to view 3D models (COLLADA 3DXML OBJ 3DS STL OFF COFF Format) and to navigate easily in these models. English and French interface.
Gmsh is a 3D finite element grid generator with a build-in CAD engine and post-processor.
Besides being a viewer, this is also a very powerful mesh editor. Meshlab supports a very wide range of 3D file formats.
Viewstl is an open source way to view Stereo Lithography Files as shaded on-screen images. Ascii STL files and dynamic rotation, scaling, and panning are currently supported.
Free STL Viewers
Simple but lightweight and fast viewer.
Unfortunately only available with German interface
MiniMagics can also analyze and section parts. English, German and Japanese versions.
Powerful viewer that can also repair, scale, cut, edit meshes and much more. English and German interface.
VisCAM View is a very easy-to-use and efficient tool to view, check, measure and communicate STL files. Visualisation of STL, 3DS, VRML, DXF, PLY, ZPR and VFX files.