In college, my favorite class was the introductory programming class. It was amazing. We used Scheme and touched upon almost every programming topic under the sun, including compilers, streams, lambda calculus, and object-oriented programming. (So, it wasn't an ordinary intro class and we didn't use no ordinary textbook.)
I haven't used Scheme much these days, but a few days ago, a colleague asked me if I knew of ways to improve the performance of Scheme code. He was wondering if there was software analogous to Python calling C or Fortran code.
I found a good discussion of fast Scheme compilers at this forum. Apparently, Bigloo allows communication between C code and Scheme code. There are also some really fast Scheme compilers like Chicken, Gambit and Chez.
One thing I've wondered is how to translate loop-heavy C/Fortran code into Scheme. My programming class hardly even discussed loops. I did find a short discussion on how to write a loop in Scheme at the MIT ab-initio wiki.
I don't have any reason to look further into this right now, but these compilers could be useful someday in the future.