Currently we have language-neutral "portal" pages for 6 of our domains, sitting at both the raw base domain and the www. subdomain. To help consolidate links and link tracking (and also to help clarify the document root names internally!) it would be good if those are normalized so a hit to the raw domain redirects to the www. subdomain:

http://wikibooks.org -> http://www.wikibooks.org

http://wikimedia.org -> http://www.wikimedia.org

http://wikinews.org -> http://www.wikinews.org

http://wikipedia.org -> http://www.wikipedia.org

http://wikiquote.org -> http://www.wikiquote.org

http://wiktionary.org -> http://www.wiktionary.org

Note that wikisource.org is *not* included here because it holds a multi-language wiki at the main domain.

See also:
T3698: Make www.$1.wiki(media|pedia...).org redirect to $1.wiki(media|pedia...).org