lisp-1 (s) give me the chills: very much prefer doubled namespaces. Though these days I focus on systems security or threat analysis. I still fondly remember the days where I could launch Emacs with sbcl and write some Montecarlo simulations on Common Lisp with electric-parens haha Those were the days of stimulating learning
It was kind of a joke intent but it gives out to better naming position although unambiguous symbols to specify a symbol; such as #' for function names. Plus now that I remember the common Lisp ANSI specification is just awesome, free and locally installable and browsable from Emacs at symbols from ages. Common Lisp images were myriads ahead in an intospectable sense, like Smalltalk. Objects and primitives can use the built-in debugger to display their inwards. The environment is just plain astonishing, moreover ten years ago - when I started - and Emacs is free as in speech and compilable from scratch, plus org-mode is awesome as well. Nowadays I feel sorry of Python introspection capabilities although hinted typing improved it so much. Not to mention Common Lisp tight generated assembly and it's garbage collector which was ahead of its own: first with Boehm and then with parallel ones. SICP was nice although nicest was the one about gravitational physics, or brownian motions, also in Scheme. Good times.