Comment by anthk

ECL will run everything SBCL can, but far more slowly, albeit the gap it's closing.

On QuickLisp, use Ultralisp, as an updated mcclim with an up to date clx it's like night and day on speed.

If you use Portacle, just run:

(ql-dist:install-dist "http://dist.ultralisp.org/" :prompt nil)

Otherwise, install Ultralisp and then eval that function to get an updated QL base).

Recommended book: https://www.cs.cmu.edu/~dst/LispBook/

Portacle which bundles Emacs + SBCL: https://portacle.github.io/