CrossOver

CrossOver (before version 6.0 CrossOver Office) is the collective name for three commercial and proprietary programs developed by CodeWeavers that allows many Windows-based applications to run on Linux, Mac OS X and Solaris using a compatibility layer. The programs include CrossOver Mac, CrossOver Linux and CrossOver Server.

The programs are tweaked, proprietary versions of the public Wine source tree with various compatibility patches added, more user-friendly configuration tools, and virtualization features. CodeWeavers employs several Wine developers and contributes code back to the free software/open source software Wine project as per the GNU LGPL, although CrossOver itself is proprietary software.