Wikimedia Downloads: Database tables as sql.gz and content as XML files

See the list of database backup dumps.
Also see daily dumps of additions/changes to content (Experimental!)
Historical material only: archives of sql/XML dumps for previous years starting from 2001

Other content

Wikidata entity dumps
Analytics data: Pageviews, Mediacounts, Pagecounts, and more, now lives here
Titles of all files (namespace 6) on each wiki, daily
Titles of all articles (namespace 0) on each wiki, daily
Static dumps of wiki projects in OpenZim format (mirrored from Kiwix)
WMF Survey data
Picture of the Year Zip or GZ files
The top 6 submissions of the WikiChallenge data competition, contains source and data
April 2011 English language Wikipedia revisions as additions/removals to the previous text
1911 Edition of the Encyclopedia Britannica, scanned as tiff files
User signup data for the Wikipedia Education Program
Sanitized Bugzilla database dump
Miscellaneous - Phabricator and SVN dumps
CirrusSearch - Search indexes dumped in elasticsearch bulk insert format
Per day aggregate WMF fundraising donation totals, amounts, and other statistics
Dumps of images and content of wikitech.wikimedia.org
Content Translation dumps in json and tmx format
XML or other files for testing use