XPize 3.2 -> this is the stable release of the 3.x series. It is only for post-install (no i386 patching and nLite support). It has, of course, many less files to be patched. It also has a different logon, wallpapers, VS, screensaver and wizard style. See a screenshot here XPize 4.0 MCE RC -> It is the latest XPize version. Many new files has been added, so there is almost a not xpized part in Windows XP. It has new logon, screensaver, VS, boot screen etc...One of the most important features is the support for 128x128 icons, perfectly handle by XPize Settings which allow you to do that and more. Some critical bugs has been fixed and the uninstaller works even much cleaner now. Remember it is still in development. XPize 4.0 MCE Lite RC -> It is the same as the above. The only difference resides in the exclusion of 128x128 icons. It is recommended for people having memory allocation errors. And as Maleko said, you dont have to install all stuff XPize includes