FAB2 Book Container

Summary

Name

FAB2 Book Container

Version

0.2

Identifiers

• PUID: fmt/2108
• MIME: application/vnd.fabylon.book

Format type

• Page Description
• Word Processor

Description

A container for digital books that stores the book as typographic data, unlike other alternatives that store books as web documents inside an archive. The container has no scripting and no executable content. Page records carry resolved line geometry, so line breaks and optical margins are decided once when the book is typeset rather than recomputed on the reading device. The signature contains an initial 16 byte magic byte header, after which it holds two little-endian unsigned 32-bit lengths, a Zstandard-compressed JSON manifest, and a chunk arena containing one compressed page block and the book's assets.

Note

Specification: https://www.google.com/url?q=https://fabylon.net/fab/specification/&source=gmail&ust=1787034048114000&sa=E Related software: Fabylon Bookmaker — writes .fab — https://www.google.com/url?q=https://www.martijnbenders.nl/bookmaker/&source=gmail&ust=1787034048114000&sa=E Fabylon Reader — reads .fab — https://www.google.com/url?q=https://fabylon.net/fabreader/&source=gmail&ust=1787034048114000&sa=E

File extensions

fab

Source

Fabylon / Fabylon

Developed by

Fabylon / Fabylon

Supported by

Fabylon / Fabylon

Internal signatures

Changelog

• Added in V125

  Release date

  7 September 2026

  FAB2 Book Container 0.2: Signature researched and samples provided by Fabylon.

  FAB2 Book Container 0.2: Full entry added. Submitted by Fabylon.