As you can see the main difference is in the close/maximize buttons. They're located at the right side and rather than making them round... the developer has made them looking like rectangles, which looks pretty darn good btw. The colors are also slightly different as well.
If you want to install them, then please go to this page for downloading and installing instructions. And remember folks... this is a metacity theme and cannot be used with Ubuntu 11.04 Natty.