Some versions of SuperMemo has said to be unworkable on CrossOver Mac, but after some try and errors, I found out that it is possible and quite workable to install SuperMemo 15 on CrossOver Mac 10.x.
The point is,
1) Install Internet Explorer 7.
2) Install SuperMemo 15 in the same bottle as IE7.
It is working quite well on my environment( Mac OS X Lion,CrossOver Mac 10.x trial version), in many modes( Basic,Professional modes).
It seems to work the same with SuperMemo 2008.
I have not tested every features, so I hope someone else could follow up.