Inside the zip there will be an installer and a "Read Me" file. Check out the read me file before you use the installer. Remember, Litestep is not for novice users, so unless you are confident rescuing your computer from mishaps, don't use it until you have read ALL the documentation on Litestep. Once you have done all that, you will probably find it an interesting program to use. Also look at "Desktop X", which allows you to do virtually the same kind of thing to your desktop without having to replace "Explorer.exe", which is your computer shell.
Have fun!!