I wrote a stack based language for the 6502 before. It's actually really trivial to do. If you have stack code that looks like this: "foo bar qux baz" and want

I wrote a stack based language for the 6502 before. It's actually really trivial to do. If you have stack code that looks like this: "foo bar qux baz" and want to convert it to assembly, all you have to do is insert JSR instructions between the words: JSR foo JSR bar JSR qux JSR baz To define subroutines, insert a label and an RTS function around code blocks. For example, to define a subroutine called qux using the code ": qux foo bar", the output would be: qux: JSR foo JSR bar RTS The last thing needed is the ability to push literals onto the stack. In my language I defined literals as things between parenthesis. I compiled them by outputting a PUSH_LITERAL assembly macro. Code like "foo (5) (6) bar" would be compiled as: JSR foo PUSH_LITERAL 5 PUSH_LITERAL 6 JSR bar That's it! You could implement an entire compiler in 50 lines of code. (of course, writing a proper FORTH requires more than this toy example)