French-speaking people have PlayerAdvance.org and Dev-Fr.org. Spanish-speaking people have ZonaDevicio. But what about the German-speaking ones? Up until now, there hasn't been a homebrew developer's forum in German.
A few days ago, I founded Dev-Szene.de which is meant to be a forum for technical discussion for homebrew developers of all systems that speak German. At the moment, there hasn't been any promotion for the site, so don't expect too much activity yet. I hope this will change during the next months.
If you speak German, go and register at Dev-Szene.de!