Apple released glossaries (translated strings of Mac OSX) for different languages. The glossaries are downloadable at: https://developer.apple.com/internationalization/#resources. You need to have an Apple Developer account; simply create one for free.
Learn how to use convert those glossaries using ApSIC Xbench.
Video: Export Apple Glossaries to TMX with ApSIC Xbench 3.0, by CATguru:
Video: Export Apple glossaries to TMX with Xbench 2.9, by CATguru: