Comment by brabel

That's cool. Another language with multiple compilers is Common Lisp, which has a dozen or so production-ready compilers (some commercial, but most free).

That allows people to use the fastest compiler during development, and the fastest runtime (or smallest memory footprint) compiler for the final release, which is really useful.

Also, just having a language specification which all compilers adhere to ensures that the language is stable and won't just break things under you (for better or worse, there are advantages for languages like Zig that can still change anything they want in order to make the language more consistent/cleaner/more powerful). I tend to value this stability a lot more these days - it lets me put all my effort in creating real value for users instead of constantly keeping up with development tools.