"The Windows Installer XML (WiX) is a toolset that builds Windows installation packages from XML source code. The toolset provides a command line environment that developers may integrate into their build processes to build MSI and MSM setup packages. WiX is an open source project, originally developed by Microsoft and maintained by Rob Mensching. You can download the latest binary and source code releases from SourceForge. This tutorial describes version 2.0, the stable release. The toolset is written in C# and requires the .NET Framework and its Service Pack 1 to run. However, this only applies to the toolset itself. The installation packages you create with the toolset do not require any extra framework or software to be installed on the target computer. Similarly, there might be a few additional utilities required for some special applications (merge modules, patches) but only on your build computer, the client will only need the finished and self-contained installer package, nothing else."

WiX Tutorial — Introduction to the Windows Installer XML Toolset