If you're working on a .Net project that has multiple environments chances are that you will be using web.config transforms that tweak environment specific values in your project.
Typically in your project you would have a base web.config file that would have all your project settings and then a separate config file for all your other environments like QA, staging or production. Sometimes you might want to preview what those config files would look like if you were to rebuild your project for that environment.
This is where SlowCheetah comes in. It's a handy little Visual Studio extension (or Nuget package) that allows you to preview what a specific version of your web.config file would look like after it gets transformed through the build process.