Maybe I have not seen the obvious: I want pretty URLs for multilanguage sites. The wiki mentions only ?lang=. Is there are way to have the language information as URL segment?

From a brief look, and I am by no means whatsoever proficient in SS, hacking sapphire's main.php and SiteTree.php should be all that is needed. But as said, I don't know the internals of SS enough to see what kind of kinky effects this may have elsewhere.

Any tips or hints ?

Thanks a ton!

Check out the how-to and recipes:

http://doc.silverstripe.com/doku.php?id=recipes:pretty_i18n_urls