“I don’t believe it’s possible to write a non-portable Common Lisp program that’s relevant to the free software community. You can try, but you will fail. Your program will either become portable or be replaced by one that is.

But it’s not all roses. We’ve invested a lot of time in adding features and fine details for our Lisp of choice that most of our friends won’t ever appreciate. I spent a few weekends working on the SBCL backend out of sheer horror at the way so many people were experiencing SLIME. I wish somehow we’d all experience it in the same way automatically.