So I've been using Scheme for a couple of years now and really enjoying proper interactive development (why would I recompile my entire program to run the tests

So I've been using Scheme for a couple of years now and really enjoying proper interactive development (why would I recompile my entire program to run the tests when I can just run the tests whenever I feel like?) and I was fairly happy with it, though I'm always very aware that using less power/time efficient languages is harmful to the environment. So I decided to give Common Lisp a try after repeatedly hearing that it's faster than Scheme and I wound up falling in love with its support for type checking (well, with SBCL's support for type checking). Now I have my interactive programming with the nicety of having SBCL warn me when I'm passing an integer to a function that expects a string or something like that. Not only does it help me make fewer mistakes while programming, the type declarations also help SBCL generate more efficient code. It's a win-win all around.