Helping contributing and collaborating (i.e., what makes it easy, what makes it hard, how to do it well, why you have to, what conflicts typically arise, fixing them)
Discussing and formulating project-wide (i.e. not language-specific) policies.
The Wikimedia Foundation is the over-arching nonprofit foundation that owns the Wikimedia servers along with the domain names and trademarks of all Wikimedia projects and MediaWiki.
Wikimedia: Overview of the Foundation (history, organisation, finances, activities)