Summarizing from elsewhere:

Thibaut Horel (User:Zaran) is interested in taking the lead on ProofreadPage work; if you have requests, please coordinate with him. He will be developing a roadmap for the development of that MediaWiki extension soon.

Àlex Hinojo (alexhinojo@gmail.com) might have requests for the MediaWiki web API (and specifically the ProofreadPage web API) that would be especially helpful for Wikisource, because he is investigating starting a QRpedia project related to Wikisource (still tentative).

Gaurav Vaidya (gaurav@ggvaidya.com) writes that querying Wikisource-specific bits like ProofreadPage:

"works pretty well! You need to make an 'imageinfo' query on the multipage image file that the Index page points to to get the number of pages; you can then query for 'Page:ImageFileName.pdf/PageNumber' to get the transcribed content for each page.

I'm currently working on a Perl module which handles this automatically, which -- with many more tests -- will hopefully make it to CPAN some day. But the source code is up at Github: https://github.com/gaurav/henderson/tree/develop/WWW-Wikisource "