(OK, view this blog post as a way for me to remind my future self where to find this stuff.)
I took a call this morning where the caller needed Portuguese translations of the fixed text in our WinForms controls. Now, we don't do these translations ourselves (we have enough problems getting it right in English, thank you very much 
), but our community have stepped up to the mark and provided their own translations for other customers to use. We host these translations and you can download them from Knowledgebase article A421.
The article provides complete instructions as to what you need to do to get these localized assemblies and how to "activate" them in your application. For reference, here are some links to help out:
If you are writing ASP.NET applications and need translated captions and the like, check out Knowledgebase article K421 instead.
I hasten to add that it's through the generosity of our customers that we are able to provide these satellite assemblies. I'd like to thank everyone who's helped — we really appreciate it — and to ask everyone: if you have translated the static text into another language we don't support yet, consider providing that to your fellow developers. Contact support if you have.