Installer is a scripting language developed by Sylvan Technical Arts and published by Commodore International for AmigaOS, first released for version 2.1 in 1992. Its grammar is based on the LISP programming language. A compatible re-implementation named InstallerLG is actively developed as of October 2018.
Example from the developer guide:
(makedir "T:fred" (prompt "I will now create the directory \"T:Fred\"") (help @makedir-help) (infos) (confirm) )
The InstallerGen tool can be used as an alternative for writing scripts by hand.