MediaWiki::API provides convenience methods for accessing the modern MediaWiki API at a low level. This is incredibly useful, but lacks the high-level abstraction necessary to maximize programmer productivity. It is used internally in MediaWiki::Bot, which provides much of that higher level of abstraction.
MediaWiki is great, also because it has an API. To really leverage the API, you need something like MediaWiki-API, which provides a perl interface to the api.
