I've deployed a MediaWiki wiki for my company. After importing all existing public domain help pages (in Chinese since we are in China), I found that there are still lots of missing ones. So I decided to contribute and translate as many as I could - that's primarily what I'm doing on MediaWiki.org.
Currently I'm not gonna translate any Manual: pages: those pages are targeting IT professionals for whom basic English skill seems to be a MUST, IMHO.
I'm a C/C++ engineer targeting technologies in computer game industry.
I wrote some PHP/MySQL stuff in 2004, as a hobby, for my personal website.
PS: I'm a Chinese who lives in China mainland.