Just a quick tip here if you use SLIME for Lisp and use Lisp as a noweb-code-mode…. Either change slime-auto-connect to 'ask or 'always or just remember to start slime before you wander into a Lisp code chunk. If you don’t, noweb-mode gets all confused and won’t code-highlight your Lisp or switch back to doc-mode when you leave that chunk.
I spent a long time just thinking noweb-mode was entirely broken if there were single quotes or less-than signs in any document chunk. Alas, it just needed SLIME to stop chucking a Not connected
error.