I don't have much beef with Ruby and RoR as I don't encounter it beyond simple web applications. In enterprise systems, dominated by Java and .NET, it is statistically non-existent. But nonetheless I was really startled when I read about concurrency "support" in both Ruby as a language and RoR as a framework. Well, basically, there are almost none in both at least at this point.

Now, in the year 2008, with multi-core CPU, "green threads" being taught in history CS classes, and with grid computing and overall drive for parallelization it is really preposterous and arrogant to think that language that has only rudimentary (if any at all) support for concurrency and a framework that is simply single-threaded (you need to start a separate processor - basically fork) can gain much attention from enterprise community. Let alone considering its scripting "baggage" and dynamic typing... It's like asking people to go back to CGI-type of web programming.

But somehow Ruby is getting popular for simple websites that have no apparent plans for growth. I guess for some having an outsider, "look, ma, no hands!" rebellion status often means much more than sound engineering and quality results...