MediaWiki and even though the Wikimedia Foundation provides a great product, it does not always provide exactly what is needed. Wikia is one organisation that has a track record of adding its own functionality on top of MediaWiki.
Wikia introduced functionality that is of a more general interest, and consequently Wikia and the WMF are working more and more together. As the Wikia software is localised at translatewiki.net, the functionality of the Translate extension and its reporting are important. It is important for Wikia to know how well the localisation for its software is doing.
To make things happen, Wikia produced specifications and wrote code that provides translatewiki with real time statistics. As the Translate extension is very much under development, the Wikia code had to be back-ported by Niklas into the live code. This would have been less of a job when the Wikia developers had used the WMF subversion.
It is wonderful to see how collaboration makes everybody a winner.