It's called Mac Blu-ray Player and it's developed by a Chinese company called Macgo. I actually caved and bought it after I got sick of pulling my hair out trying to get my BD drive working in Windows on my 2008 MP.
It uses an Internet connection to talk to an AACS/BD+ server to decrypt the content on commercial discs. Windows-based players do the same thing, actually. Set-top BD players don't need an Internet connection because they're assigned the proper credentials already in firmware.
And the movie industry can't understand why some people do all they can to strip out the DRM from the films they buy