ruby versions api compatability

Hey Jeroen, thanks alot for your Ruby roundtable discussion at FUDCon. I was looking around for various solutions to the Ruby version compatibility problem for Fedora/Yum and recalled the 'alternatives' utility which I believe might help out w/ this problem as well. It is shipped as part of the 'chkconfig' package so it's pretty standard on Fedora, and was (according to the manpage) originally written for this same problem w/ Perl. http://linux.about.com/library/cmd/blcmdl8_alternatives.htm I recall using it a while back to install various various of Java side by side in a single environment (pretty good overview here http://lanestechblog.blogspot.com/2008/03/using-alternatives-in-linux-to-...). I could see this being useful if we wanted to support installing many different versions of the Ruby interpreter or different Ruby interpreters entirely side by side on a single system. One thing I'm not currently sure of is how we would handle the different ruby lib and gem paths depending on which alternative is setup. If we can swap in the correct lib / gem path depending on which alternative is selected (systemwide or by the user) we should be good. Any thoughts on this? It might be a little more complicated than doing the different vendor/version site dirs alone but might provide a nice way for multiple version support. -Mo