I've just created
https://lists.wikimedia.org/mailman/listinfo/offline-l
as a new official WMF location for discussions about both offline reader and editor technologies. Please let me know if you'd like to revise the list description or volunteer as a moderator. This deprecates the old wiki-offline-reader-l mailing list which was never actively used, so I haven't bothered to port the archive.
All, please consider whether you should be on this list, and if so, subscribe directly through the URL above. It should help us to standardize file formats and software approaches, and will also help WMF to identify where it can usefully invest resources.
Samuel, can you help get the word out about this new list?
Thanks and all best, Erik