It's a scheme to C compiler (with an interpreter, of course) that implements Cheney-on-the-MTA compilation (so continuations are almost free), a very nice macro system (although with some unfortunate performance implications), and has a relatively large library repository (for a scheme), as well as an stdlib that emphasizes practicality over purity (it even includes a regex library in the default install) while still keeping the simplicity that makes me love Scheme: I can keep the whole language in my head. Plus, if it doesn't have the library you need, writing C bindings is a piece of cake (because it compiles to C, anyways).
It's a scheme to C compiler (with an interpreter, of course) that implements Cheney-on-the-MTA compilation (so continuations are almost free), a very nice macro system (although with some unfortunate performance implications), and has a relatively large library repository (for a scheme), as well as an stdlib that emphasizes practicality over purity (it even includes a regex library in the default install) while still keeping the simplicity that makes me love Scheme: I can keep the whole language in my head. Plus, if it doesn't have the library you need, writing C bindings is a piece of cake (because it compiles to C, anyways).
Awful is the name of its web framework.