From Ross-Tech Wiki

1.8 Will there be a Mac or Linux version?
There will be no "native" Mac or Linux versions. The time and effort required to "port" VAG-COM to these platforms would never be worthwhile. One person has gotten VAG-COM running under Linux using WINE -- click here for details. Another person has managed to get VAG-COM working on a MAC with Virtual PC - click here. Neither of those examples are supported by Ross-Tech.