Consider Forth. The simplicity of the language's syntax means that a compiler is basically just a table lookup, and they can fit into just a few kilobytes of c

Consider Forth. The simplicity of the language's syntax means that a compiler is basically just a table lookup, and they can fit into just a few kilobytes of code. Even if you don't port or implement an actual Forth, a Forth-like threaded code model fits tiny memory constraints very well, with very high code density and only moderate overhead. If you add a couple registers to the VM for easing pointer access, it becomes a suitable target for C-like languages, too.