RooCategory in RooMCStudy

You can compile your preferred version of ROOT yourself: [url]Installing ROOT from Source
The only problem is the disk space. You will need something like 640 MB in order to build it (you can unpack and build ROOT in “/tmp”, for example) but afterwards you will just need something like 220MB for the “installed binary distribution” (and the “source code and building” subdirectory can be removed).