Common Lisp systems have supported two ways to develop software: a) fast incremental development of Lisp code. For that one got Lisp interpreters (executing th

Common Lisp systems have supported two ways to develop software: a) fast incremental development of Lisp code. For that one got Lisp interpreters (executing the code on the s-expression level) and quick incremental compilers. Code then tends to be more on the dynamic side with full debug information. b) delivery of optimized applications for deployment. We got optimizing native-code AOT compilers (using type hints and type inference), block compilers (optimizing larger batches of code), whole-program Lisp-to-C compilers and application delivery tools with tree shakers. Code then tends to be more on the static side with little or not debug/development information. Between a) and b) there is a continuum of different approaches - often in the same program in different code sections - where compilers may support different code generation strategies. Thus one can develop using an interpreter or fast incremental compiler, and then deliver with an optimizing compiler.