Allegro library for C (mostly used for game and multimedia apps programming) used its own container file format.
In general, it allows storage of arbitrary binary data blocks bundled together with some simple key-value style metadata ("properties") for every block. Allegro also pre-defines some simple formats for bitmaps, fonts, MIDI music, sound samples and palettes. Allegro library v4.0+ also support LZSS compression.
This spec applies to Allegro data files for library versions 2.2 up to 4.4.
This page hosts a formal specification of Allegro data file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.