[_19qg]

I would think that none of the available options provide a complete integrated development environment as LispWorks and Allegro CL (which are commercial, but still they exist and are available) do.

The combination of SLIME/GNU Emacs and SBCL has some unique features (and is really a very useful combination), but the whole integrated development feeling one won't get from it. For example the LispWorks IDE is completely written in itself, is fully GUI based and is also in one application. Thus the cross-platform GUI system used to write the IDE is also available to the application developer. GNU Emacs OTOH is an external application, not written in Common Lisp and with a clunky user interface.

Then there is a path of older and mostly abandoned, but powerful and/or very usable user interfaces: examples are Xerox/Medley Interlisp (https://interlisp.org), Symbolics Genera, Macintosh Common Lisp and others.