Nullsoft Scriptable Install System (NSIS) is a script-driven installation system for Microsoft Windows with minimal overhead backed by Nullsoft, the creators of Winamp. NSIS has become a widely used alternative to commercial and proprietary products like InstallShield, with users including Amazon, Dropbox, Ubisoft, BitTorrent, and McAfee.
NSIS is free software released under a combination of free software licenses, primarily the zlib license.
NSIS can be extended with plugins that can communicate with the installer. Plugins can be written in any managed programming language capable of building a dynamic-link library, and they can be used to perform installation tasks or extend the installer interface. A plugin can be called with a single line of NSIS code.
Several plugins come with the NSIS package that permit the installer to display a splash screen, display a custom page, display an image on the background, download files from a website, perform mathematical operations, patch files and more.
Other plugins are available online, including ZipDLL, and a Python plugin.
- Very small overhead (34 KB)
- zlib, bzip2, and LZMA compression
- Plugin support
- Script preprocessor