NSIS (Nullsoft Scriptable Install System) is a professional open-source tool for the development of Windows installers. It is designed to be as small and flexible as possible and is therefore highly suitable for internet distribution.
NSIS 3.0rc2 is the second and hopefully last release candidate for NSIS 3. It contains a fix for nested ${Switch} statements and some minor fixes.
Download:
http://nsis.sourceforge.net/Download
Release notes: