While Inno Setup is a tool to create installers for Microsoft Windows
applications, innoextract allows you to extract such installers without using
Wine. In particular, innoextract supports GOG.com installers and Arx Fatalis
patches.

To extract a file to the current directory, run:

$ innoextract <file>

A list of available options can be retrieved using:

$ innoextract --help

Documentation is also available as a manpage.