Erik Moeller, 13/11/2013 06:51:

We're re-implementing the rendering pipeline for Collections to ensure long-term maintainability, and our default would be to eliminate initially all formats except for PDF if we don't absolutely have to support them. I'll see if we can get some metrics on current ZIM file usage via the Collection extension, but it'd be nice to get qualitative feedback as well.

(More background at: https://www.mediawiki.org/wiki/PDF_rendering )

All including ePub (cc Wikisource-l).

Nemo