I'm currently employed by Wikimedia Germany as a software developer, which sometimes includes working on MediaWiki.
Licensing policy: I hereby place all my textual contributions to usability.wikimedia.org into the public domain (if this should not be possible by some legal technicality, I grant anyone the right to use, modify and distribute, without any restrictions or conditions with regards to copyright). This only applies to my own original work of course, not when I import or copy other people's work. It also does not automatically apply to images and other media files, nor to program source code, nor to my contributions to other wikis, on Wikimedia sites or elsewhere. Note that the above statement shall not be taken to waiver any personality rights.