From Just Solve the File Format Problem
NSIS Script is a scripting language used by NullSoft Scriptable Installation System (NSIS), a program that generates Windows installers. Files referenced by the NSIS script are bundled together by a compiler into an Portable Executable file (see NSIS for details on the subset generated by NSIS), which can then be distributed as an installer. The scripts control the behavior of the installer interface, as well as the installation process itself. NSIS notably does not generate files of the MSI format , which has in modern (2019) times become a common way to distribute Windows software.
Regular NSIS script files have the extension ".nsi". Those intended for usage as headers have the extension ".nsh".
- NSIS SourceForge Page
- NSIS Wiki
- NSIS Users' Manual
- NSIS Scripting Reference
- Wikipedia:Nullsoft Scriptable Install System