> Good to know, up till now I thought wikibase was still a mediawiki extension :s
It is. But it consists of several components by now, some of which are
independent of MediaWiki.
I don't agree with that use of the terminology. The website defines it as follows: "Wikibase is a collection of applications and libraries for creating, managing and sharing structured data."
This includes Wikibase Repository and Wikibase Client, both of which are MediaWiki extensions.