I'm going to riff on what Null-Set said about Ada, which people like to criticize for its complexity but which actually solved a lot of hard problems in very cr

I'm going to riff on what Null-Set said about Ada, which people like to criticize for its complexity but which actually solved a lot of hard problems in very creditable fashion for its day. The complexity complaints are a joke, considering that that both Java and C++ have since become more complex than Ada ever was by trying to solve some of the same problems -and in C++'s case largely failing. If Ada (or its relative Modula) were introduced today, it would seem like a breath of fresh air compared to those two. Special runner-up: MOOcode, the native language of LambdaMOO. Still one of the most coherent and pleasant object-oriented languages I've used. It's especially notable for its "code runs as author not invoker" protection model and call-stack introspection. People could learn a lot from that. My first thought was Nim, and o2348diuu already explained why. Second thought was Lua, but a couple of people beat me to that. Haskell and Elixir are definitely not underrated. They're underused, certainly, but that's not the same thing and IMO Haskell is often overrated.