MZ Scheme links trivially to C libraries. I would think that anyone who uses Arc would use this facility heavily. Now whether there exists a C library to do exactly what you want is a different question. And I know this might be heretical here, but ROR is hardly the great time saver the fanboys make it out to be when you count in issues like deployment and doing non standard things with it. (Don't get me wrong, it is a good framework, but it is hardly a magic wand and neither is it very unique - Wicket + scala comes very close to ROR in productivity for example)
PS: How long do you think it would take before people hack up a virtual machine or C code emitter? I, for one would do exactly this if I planned to use it in my startup. It isn't that hard (Ruby's recursive descent sloooww interpreter still powers all those RoR sites, minus the vanishingly few ones in JRuby.)
I've dealt with a couple systems that link Lisp 'trivially' to C. When they say they link trivially, what they mean is that they let you call the function in the C library just like you'd call it from C. This is frequently extremely not how you want to do it in Lisp, and so you're forced to either a) write a Lispification layer, in which you take all the C functions and turn them into a library that acts like you want a Lisp library to act (the usual approach), or b) just write it like it's in C, which makes you very angry all day long, and also loses some of the benefit of writing in Lisp. Both approaches slow you down quite a lot. Especially if you decide not to be an asshole and release your lispification layer as open-source (which you should)-- because then people will all be pounding down your door for fixes and extensions and maintenance for new versions of the C library, which is not what you want to do. You didn't even want to write the layer to begin with, presumably.
So no, 'trivial' C linking not actually a silver bullet making everything hunky-dorey with respect to lack of libraries. Python has a significant advantage in that it's popular enough for many people to have already gone through the Pythonification process for most important libraries, and have also open-sourced their Pythonification layers.
MZ Scheme links trivially to C libraries. I would think that anyone who uses Arc would use this facility heavily. Now whether there exists a C library to do exactly what you want is a different question. And I know this might be heretical here, but ROR is hardly the great time saver the fanboys make it out to be when you count in issues like deployment and doing non standard things with it. (Don't get me wrong, it is a good framework, but it is hardly a magic wand and neither is it very unique - Wicket + scala comes very close to ROR in productivity for example)
PS: How long do you think it would take before people hack up a virtual machine or C code emitter? I, for one would do exactly this if I planned to use it in my startup. It isn't that hard (Ruby's recursive descent sloooww interpreter still powers all those RoR sites, minus the vanishingly few ones in JRuby.)