CADSpan is optimized for the Z Corporation line of 3D printers

General Purpose .stl Mesh Repair Tools
Magics
VisCamRP
DeskArtes
MeshWorks

Point Cloud Resurfacing Tools
Raindrop Geomagic www.geomagic.com
Paraform PolySurf www.paraform.com

Stl Pugins and Tools
Floating Point Solutions www.fpsols.com

2d to 3D plugins

Polygon Mesh File Format translators
Importers/Exporters and Mesh Viewers
NuGraf and Polytrans
Deep Exploration
KANDU - Cadmover

CAD Data converters
CADfix 

Polygon Mesh Reduction
3D Compress www.3dcompress.com