Not sure if this is the proper thread for you to address this, but I'm curious as to whether you think there would be in value to something like Arc -> C/Java/?
for libraries/frameworks/speed
Arc is intended to not be attached to any other language or VM. That's not to say you couldn't implement your own Arc runtime on top of a language of your choice. In fact, since there are already Schemes that run on top of both C and Java, you could do so simply by porting the Scheme parts to an appropriate Scheme. It's under 1000 lines of Scheme.