TIL that there is a whole package for “Common Lisp Emulation”[1] in Emacs that adds functions and control structures from CL “to make Emacs Lisp programming significantly more convenient”. Never developed a package for Emacs myself, but I feel like this can be of great help if I ever wanted to.
I know that there are projects like Lem[2] that try to build some kind of editor (Emacs-like, I guess) on top of CL, which made me wonder if we would have a CL-based Emacs today if it would have been standardized by the time and if this would have been a better choice than creating a custom dialect.
It's the command set (key bindings, extended commands, ...), buffers with modes and minor modes, the user interface for buffers, marks, the "cursor", extensibility, ...
For example in a typical Emacs the "cursor" / current mark is always visible, even in GUI versions. This is very different from other editors, where the current cursor can be non visible.
Basically there are a lot of similarities between the early Emacs editors (EMACS, EINE/ZWEI/ZMACS, Multics Emacs, ... and others).
Does LEM try to be similar to an EMACS editor or is it only emulating one on demand?
GNU Emacs use might also think of Emacs Lisp as an extension language, a GUI version, menubars with menus, self-documentation, ...
Theological questions. The reality is that one "knows an emacs when one sees it." And lem behaves like GNU Emacs in some fundamental respects. Default keybindings, buffer management, macros, etc. Even newer things like lsp support + modes, etc.
It is not clear to me why the marketing for lem is "a Lisp IDE" when it clearly is "an emacs written in Common Lisp"
I know that there are projects like Lem[2] that try to build some kind of editor (Emacs-like, I guess) on top of CL, which made me wonder if we would have a CL-based Emacs today if it would have been standardized by the time and if this would have been a better choice than creating a custom dialect.
[1]: https://www.gnu.org/software/emacs/manual/html_node/cl/ (C-h R "cl" in Emacs)
[2]: https://lem-project.github.io