If I'm not mistaken, wasn't Clean closed source and commercial for a long time? I was very interested years ago, but I kept on thinking that without opening up

If I'm not mistaken, wasn't Clean closed source and commercial for a long time? I was very interested years ago, but I kept on thinking that without opening up it would eventually just fade into oblivion and never went beyond the toying phase. A common fate for the many languages with a single and commercial reference compiler/interpreter.