For example, want to experiment with programming languages? You must plough your way through parsing (a solved problem) and maybe some variety of VM to emit cod

For example, want to experiment with programming languages? You must plough your way through parsing (a solved problem) and maybe some variety of VM to emit code for before you can even start actual work. Why? If you're just trying to experiment with language, why not write a simple syntax tree interpreter? Save the full, production-grade implementation for when you've experimented enough to know more or less what you want to implement.