NInstall
A project to produce an open source package that can compete with the commercial installer products under Windows using the windows installer (msi files). Will support patches and upgrades.
Windows Installer XML (WiX)
The Windows Installer XML (WiX) is a toolset that builds Windows installation packages from XML source code. The toolset supports a command line environment that developers may integrate into their build processes to build MSI and MSM setup packages.