From the developers site
FairMount is a tool that allows decryption of DVD content on the fly for a convenient access. FairMount does not perform the actual decryption, it simply forwards the data to VLC Media Player which is used for decryption - thus, VLC Media Player must be installed for FairMount to work.
NB: The only DL link is to download fairmount with dvdremaster which is a paid app, but after the download just extract fairmount from the .dmg