Creating your own programming language

Has anyone here every created their own programming language? What was the syntax like, and what did you use to implement the language? Using Haskell to implement your language is cheating BTW, so don't even post here if your language is made from Haskell.

Serious answer is serious:

If you just want a VERY easy to implement language that coders (probably just yourself) will use, then go for stack-based.

If you need anything else, jam a DSL on top of Lisp with its macro system.