The ProofreadPage extension is an essential tool for Wikisource. Essential because it is installed on every Wikisource. As you can see from the screen-print, it is a tool that helps with the work flow of transliterating a text to the computer. The example is an old French text and in yellow it says that the transliterated text conforms to the scan.
It is an essential tool with one potential problem: its primary maintainer ThomasV has abandoned it. With the upgrade to MediaWiki release 1.19 several bugs surfaced and they were documented on the Scriptorium of the English language Wikisource. This was done by one of the very active Wikisourcerers, user:Billinghurst.
This problem was signalled by Lars to several WMF notables. Indeed there are plenty bugs registered in Bugzilla for ProofreadPage including patches. It is however really cool to notice that Sumana is finding reviewers for them and it is wonderful to learn that ThomasV was only one of more then sevendevelopers committing code in the last couple of months.
Tender loving care is needed to make sure that it will continue to work well after the MediaWiki release 1.19 and it is wonderful to learn that Zaran indicated his willingness to take over as its primary maintainer. One of his first tasks is to identify the existing relevant patches and integrate them.