Winstep Xtreme theme
A Winstep Xtreme theme is a theme/skin for Winstep (not related to NeXTSTEP, despite the name), a suite of Windows "desktop enhancement" programs that replaces the default shell and adds "widgets" to the desktop, originally written by Jorge Coelho and John T. Folden. Winstep Xtreme themes can also set the desktop background. The website claims that it is available for up to Windows 10, but it seems like these things had their heyday in the Windows XP era, when extremely elaborate GUI decorations were newly possible, and therefore a novelty.
A Winstep Xtreme theme is a ZIP file containing (in a flat directory structure) the main (shared) theme images, as well as elements specific to its subprograms, which are:
- Winstep Software Technologies - Products Page: Official website
- : Many themes on wincustomize.com
-  More on skinbase.com
- : Manual