I do embedded development, and I use perl to help me debug my designs. However, I should add that so far I haven't needed to do anything faster than "serial port" speeds. Also, I don't need any "low-level" access to my computer's hardware.

If these apply to your situation, then I'd suggest you look into perl. It's great for ad-hoc programming, and CPAN has a rich collection of general purpose modules. For instance, the Test Anything Protocol has a large suite of supporting modules, and you really can use it for testing anything, not just perl code.