This isn't an exact answer to your question, but I have to say macros. Going from CL (and scheme probably too) to macros in any other language is like going fr

This isn't an exact answer to your question, but I have to say macros. Going from CL (and scheme probably too) to macros in any other language is like going from a lambo to a tricycle. It's one of the things I miss most about CL. I also love the live-editing aspect of CL. When I was doing game programming with it, being able to replace functions while running was incredibly useful. You don't have to re-create all your state, you can jsut live-edit a function and boom fix a bug or add a new feature right there. Very good for exploratory programming with lots of otherwise-hard-to-replicate state.