Skinny is a program meant to help the user in patching the system, replacing the original component, uxtheme.dll, with a custom one that allows the system to use non MS-signed themes.

The user, after the patch, will be free to choose between hundreds of high quality themes available for download (mainly for free) from many internet sources, rather than from the scarce pool of choice of MS-signed themes, but of course the system will still be able to use MS-signed themes via the custom uxtheme.dll.

Due to the unclear license status of the patched uxtheme.dll versions available online, generally distributed as free for personal use, the dll itself is not included in the program and it must be downloaded separately by the user from one of the many sources available on the net.