Apple, here you will find a lot of information about how to localize software intended to run on Apple’s OS X and iOS. In order to be able to download glossaries etc. you will need to register as a developer, which is free of charge.
Canoo contains comprehensive information about German linguistics such as grammar and spelling etc.
Well this is a sorry excuse for a terminology resource but it will have to do until IBM get their act together and present something more worthy.
Here is a list of Mozilla glossary files from previous releases for reference. Translation consistency and quality can be greatly improved if there are glossary files for reference.
Over 7000 glossaries collected by the Portuguese translator J. Roque Dias. Very impressive
Novell Corporate Localization Services, there are also Translation Style Guides, you'll find them if you look around. As of the latest update this is, as you will see, a site more devoted to Suse (linux) but it is still valid as a good resource of information.