UxStyle is described as 'An easy way to allow the install of custom themes on Windows. UxStyle is our solution consisting of a light-weight system service named Unsigned Themes, complimentary to the Themes service, and a kernel driver' and is an app. There are three alternatives to UxStyle for Windows. The best alternative is WindowBlinds. It's not free, so if you're looking for a free alternative, you could try UltraUXThemePatcher or SecureUxTheme.
WindowBlinds is a computer program that allows users to skin the Windows graphical user interface. It has been developed by Stardock since 1998, and is the most popular component of their flagship software suite, Object Desktop.