I have only used ruby for writing little scripts. Things that are typically done using Perl/awk/bash... Ruby has the potential for much more, but there doesn't seem to be a problem domain where it truly excels. Maybe Rails, but that's a bit controversial (would it carry large websites like Amazon or Facebook?). On the client side Javascript seems to be the big winner. It is the plugin language for Firefox, and in the future it may even become a standard choice for desktop software development (with Adobe Air). So where is ruby nowadays? For what kind of software would ruby be the programming language of choice?