(In the context of T94165: Engineering Community quarterly review January - March 2015, WMF is changing its quarterly review process, and this is a goal task created basically after the fact in order to accommodate to the new process.)
The following text is extracted from the last quarterly review, and eventually fine tuned:
Expected impact: MediaWiki 3rd party agenda contributing to Wikimedia's plans
Success measures:
- The group grows and registers regular activity.
- They maintain a wishlist of MediaWiki features interesting for third parties.
- Their requests to the Foundation are documented.
- They benefit from the Wikimedia infrastructure, activities, and support.
- They investigate alternative sources to develop MediaWiki features.