On behalf of the LazySlice team (BookOwl and I), I would like to enter LazySlice, a dependently typed Lisp. If you've ever used Agda or Idris, LazySlice is based around a similar theory, but it's Lispy!
For me, this contest was an opportunity to learn how to implement a dependently typed language. Doing so is tricky because typechecking and evaluation are intertwined. Implementing dependent pattern matching, in which matches can refine the type of a term, was especially challenging for me.
See and edit the file in the examples directory.
EDIT: I attached the repl, which was in Haskell, but for some reason it's appearing in Bash? Sorry, I'm new to Repl.it...
EDIT 2: Try this link: https://repl.it/@lazyslice/lazyslice