See the FAQ for the differences between the two builds.
FWTools Build (Recommended)
OpenEV is distributed as part of the FWTools package for Windows and Linux, which includes support for more file formats, and also contains free GIS utilities in addition to OpenEV (Mapserver, PROJ.4 utilities). The FWTools packages are released quite frequently, and track the CVS version of OpenEV fairly closely.
Downloads for Windows and Linux are available at FWTools
Vexcel released version OpenEV 1.80 in July 2004. It is available for:
Older releases of OpenEV are available from the SourceForge Download site.
The OpenEV source code is available through CVS.