[DanBC]

A decent master file system is good. Including conversion is sub-optimal. Have a sister project that creates and maintains good software for conversion.

That would draw 2 crowds; people wanting to help PG and people unwilling to continue using Calibre.

[felix_faber]

IMO, calibre is two-way. From any file format to any other.

That is _hard_ to do really good. Text is the easy part. What about tables? What about image captions and footnotes?

What such a project would need is one master file format from which other formats are derived. But not the other way around.

Having disjoint repositories for books/software is a good idea though.