When people say they've designed a language, I go; me too!
A statically typed language for the Erlang VM (beam). Sports (or rather, might
some day) a Hindley-Milner row-polymorphic type system, abstract patterns, typed
simplex process communication, math with rationals and infinitesimals (using the
Levi-Civita field). Compiles to a statically linked ELF binary.
Unfinished; now and, in all likelihood, forever. It's a vehicle for me to learn things.