I wrote Guile wrappers for a few of the functions in fpgatools, free software tools for Xilinx FPGAs. Here's my translation of their "hello world" example from C to Guile. It's pretty ugly still, but better than the original, IMO: https://gitorious.org/davexunit/guile-fpga/source/examples/hello-world.scm

I think it would be really neat to write a HDL as a Guile DSL, but I need to actually know what I'm doing before attempting that.

Now, I can't actually use any of the bitstreams generated by fpgatools on my Novena because the FPGA model is unsupported. I hope to help change that. We'll see how it goes.