LZEXE

File Format
Name	LZEXE
Ontology	Electronic File Formats Compression Executable compression LZEXE
Released	1989

LZEXE is an executable compression utility, developed by Fabrice Bellard. It compresses DOS .EXE files.

Identification

LZEXE-compressed files normally have ASCII "LZ09" or "LZ91" at offset 28.

As with most compressed executable formats, more-robust identification is possible, by looking for the characteristic decompression code.

Software

Compression software

• LZEXE
  • v0.90 (1989-10-30)
  • v0.91 (1990-01-02)
  • v0.91e (1990-10-15). Alternate link: [1]
• "LZEXE v1.00a" by IS2 France Diffusion. Seems to be functionally identical to LZEXE 0.91.

Static decompression software

• UNLZEXE - A widely-distributed open source utility that does static decompression of LZEXE-compressed executables. Originally by Mitugu Kurizono (Kou). Versions "0.6" and above include patches by other authors, and might be unofficial.
  • v0.2 (1990-03-29)
  • v0.4 (1990-05-12)
  • v0.5 (1990-05-17)
  • v0.7
  • v0.8
  • https://github.com/mywave82/unlzexe - Modernized source code
• mz-explode
• Deark (with -m lzexe option)
• Rizzle

Dynamic decompression software

• UNP - An example of a dynamic decompression utility for DOS

Protectors

(utilities that modify a compressed file to make it more difficult to identify and/or decompress)

• ANTI-UNLZEXE
• LZALT v0.03 by Codon Software
• LZEALT v1.04 by De Trans Software

Links

• LZEXE home page
• Reversing LZ91 from Commander Keen (This is reportedly[2] about LZEXE.)