What are you on about? The Agda compiler, Pugs, Cryptol, Idris, Copilot (not that copilot you are thinking of), GHC, PureScript, Elm… These might not be mains

What are you on about? The Agda compiler, Pugs, Cryptol, Idris, Copilot (not that copilot you are thinking of), GHC, PureScript, Elm… These might not be mainstream, but are (or were for Pugs, but the others are current) important within their niche.