I have not yet seen this software but the announcement sounds interesting. For one thing, I am not used to seeing much genealogy software produced in Iceland. For another, the word "Osk" means wish in Icelandic. Here is an excerpt from the announcement of Osk version 4.0:
Studlar Software has updated Osk, a genealogy application for Mac OS X and Windows XP, to version 4.0. It’s a Universal Binary update, so runs natively on both PowerPC and Intel Macs.