ActiSetup Description:

ActiSetup is an advanced setup development environment for Windows Installer. It supports authoring MSI installation packages, merge modules, and patches. It allows you to create installation packages for your software products, with maximum ease of use and flexibility. With ActiSetup, you can quickly create installations with a single step-by-step wizard, as well as directly edit the MSI tables for greater fine-tuning.

ActiSetup also includes an updater service, so you can deliver patches to users of your application reliably and efficiently. Finally, ActiSetup includes a setup bootstrapper, designed to simplify the process of installing prerequisites such as the .NET Framework.