This is correct. Greenspun's Tenth Rule is not meant to be interpreted as applying to projects that are consciously creating a Lisp implementation. It's about programs which are not meant to be language implementations at all reinventing ad hoc infrastructure that is designed in Lisps according to established patterns. For instance, badly reinventing something that functions as symbols.
If you are creating Lisp because you want to create Lisp, like creating Lisp, want to show off creating Lisp, that obviously is not what the Law is about.
Furthermore, if you create Lisp because you know the Law, know it is inevitable, and want to avoid the caveats and missed bars by doing so explicitly, well then that also is not what the Law is about.
But if you are going about your business, focused on your independent goal, realize you need Lisp like lists, and then 250 lines of code later realize you have created a solid Lisp unintentionally? Well, congrats on falling into the trap but not getting hurt!
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Personally, I have created both Lisp and Forth multiple times for suitable projects where I wanted some flexible runtime scripting. I am not familiar with the standard version libraries of either and don’t need them.
Minimal foundation implementations are extremely easy to create, and eliminate any dependencies or sources of mystery.
Anyone know of any other well designed mininal languages?
The corollary to Greenspun’s rule is that any sufficiently complicated Common Lisp program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Prolog.