Sumatra PDF is a PDF, ePub, MOBI, CHM, XPS, DjVu, CBZ, CBR reader for Windows

Why no support for JW.org's JWPUB DataBase format

Is it possible to add the JWPUB format?

(note: I am not a Jehovah Witness - I just want to
be able to see their free study bibles in this JWPUB)

I"ve extracted it’s contents and it seems to be a heavily modified EPUB format.

I don’t think it is anything like a Publishing format (certainly not epub)
The sample I saw appears as a zip wrapper over a zip wrapper over a
Structured Query Language DataBase with inefficient use of duplicate images.

SQLite version 3.28.0 2019-04-16 19:49:53
Enter “.help” for usage hints.
sqlite>
image

from others anaysis it appears the database wrapper may then download other data in the background
see TheocBase - ASL Meeting Workbook Import from JWPUB file

Certainly its more convoluted than it needs to be and potentially more problematic than drm protected azw.

More recently the choice of formats has been expanded so magazines and many bibles are now multi-format at Online Bible—Read, Listen or Download Free: PDF, EPUB, Audio (jw.org)

I highly doubt that kjk will be interested in putting in so much work to add support for such a niche SQLite DB-based ‘ebook’ format. Frankly, there are far better things to do.

Sorry, by that I meant ebook format, not strictly ePUB - I used it as an example, since I don’t know much abot code.

In the future, maybe?

But I’m glad for the feedback, anyways,

SumatraPDF is perfect - I only use Adobe against my will - for those “pain-in-the-ass” PDFs that take ages to view the next page.

@WilliamVieira
There are many different structures used for storing written materials in a “book” format.

A DataBase format has its uses for building a library of document pages/objects that can be queried and accessed at random just like hyperlinks.

The basic concept of ePub is to bring many of those different document structures down to one universal open source standard as single files with links to both internal embedded contents (such as media) and other external links for cross reference.

JWpub is nothing like that. It is proprietary (not open source) and its structure is more like an Access Database that can link to other online database objects. It is not widely used by the general global public even if it is Internationally used around the world.

For those reasons I do not think it is a suitable candidate for inclusion.

Re: your comment about speed of opening next page , there are reasons for different versions working faster or slower with certain files so can I suggest you try a portable version of pre-release to acertain current behaviour and if there is a specific file causing issues report it to sumatrapdfreader/sumatrapdf · GitHub Issues

Please support JWPUB format!

SumatraPDF uses Open Source rendering for PostScript (Public Format) PDF (Adobe only Some Parts are OSS) PNG (OSS) JPG (Most are OSS) ePub (Public Format) TIFF (Adobe Public format) and some other formats that are less common such as HEIC (some OSS libraries) WebP (Google Open Source) TGA (AT&T/Pinnacle Previously Published but Technically proprietary, however not exploited.) & Mobi/AzW1 or 2 (Now Amazon legacy e-book format)

However JWPUB appears to have no public or published open source, thus should / can not be generally included in an Open Source Application

The only related apps on GitHub currently are jwpub · GitHub Topics · GitHub
At present none of those would extract the contents for viewing.