NSIS (Nullsoft Scriptable Install System) is a professional open source system to create Windows installers. It is designed to be as small and flexible as possible and is therefore very suitable for internet distribution.
Rated 50/50 by guti at Mar 31, 2008
Althought it lacks a native Win64 port, and still has no BCJ filter for compressing EXE, it is the best installer tool.
Rated 50/50 by jcollake at Apr 24, 2008
Fyi on previous comment: BCJ & BCJ2 is included with LZMA, which I assume most people will be choosing with NSIS. The most critical thing is to enable BLOCK support so the whole bunch of files is essentially TAR'd together first. This improves compression substantially since the LZ 'dictionary'/window spans across all the files.
Rated 20/50 by mkeeley at Oct 13, 2008
I used to use and support NSIS all the time as it used to be a simple elegant yet powerful solution however as time has gone by it has become a clunky mess. Now use InnoSetup and can't see a time I'd go back unless NSIS was re-written from scratch.