> Types / Type-driven development Rating: Best in class

> Haskell definitely does not have the most advanced type system (not even close if you count research languages) but out of all languages that are actually used in production Haskell is probably at the top.

What are these other research languages, that have such incredible type systems? Do they usually have implemented compilers, or would they only be described in an abstract form? Can I explore them for fun and curiosity?