OSDev (foreign language)

French

• http://a.michelizza.free.fr/pmwiki.php?n=TutoOS.TutoOS
• http://sos.enix.org/fr/SOSDownload

German

• http://www.lowlevel.eu/ (Forum: [1]; IRC: irc.euirc.net, #lost)
• http://www.henkessoft.de/ (Forum: [2])

Japanese

• http://wiki.osdev.info/

Polish

• http://osdev.pl/ - Site about Open Source, doesn't seem to be really about OSDev.

Portuguese

• http://www.dei.isep.ipp.pt/~orlando/so2/

Russian

• http://osrc.info