Is WindowBlinds the only program that can open .wba files?

I recently looked into changing the theme for my Windows XP, because the built-in themes are kind of bland. Most of the themes I find are .wba, which you need WindowBlinds to open. However, WindowBlinds is about $30, and after the free trial ends my theme will go back to normal. I might purchase WindowBlinds, but before I do I was wondering if there any free alternatives.