However I have been writing my own BASIC interpreter recently and while the RPi wasn't initially in the viewfinder (as it were), I've had more than enough interest in it to actively make sure it works OK on the RPi and support it.
However the only thing I can really produce right now is a binary .DEB package - OK for the Debian release, but maybe not for the RH/Fedora type releases unless you're happy to install a .tgz file... However I'll be putting the sources online so maybe someone else can produce a suitable package for it.
I don't have a build setup, but RH's .spec is a fairly simple file to write. (basicly gives all the instructions for pulling down, building, and packaging a .rpm). I'm pretty familure with it because pkgbuild for Solaris' IPS uses (slighly extended) the same fomat. If you wanted me to, I could wack one out in a day, easy.