AATranslator is a Windows application that can convert sessions/projects from many diffferent DAWs into other formats. At the present time (December 2012), it can read and write Ardour 2.X sessions, and can read Ardour 3 sessions.

The program runs very well on Linux using Wine (a Windows environment for Linux). There are equivalent solutions for running Windows applications on OS X, but we have no experience with them at this time. Ardour users have reported great results using AATranslator on Ardour 2.X sessions.

The AATranslator website has full details on supported formats and DAWs. The list includes ProTools, Live, Reaper, OMF, AAF and many more.