Lean 4
Theorem prover and dependently-typed programming language.
Lean 4 is the current generation of the Lean prover, used heavily by mathematicians (the Mathlib library is the largest formalised mathematics corpus) and as a general-purpose language for verified software.
Install
curl https://raw.githubusercontent.com/leanprover/elan/master/elan-init.sh -sSf | sh
