There’s history here. Green threads are as opposed to native, you both agree on that. The original green threads were pretty weak and behaved as described above

There’s history here. Green threads are as opposed to native, you both agree on that. The original green threads were pretty weak and behaved as described above. People use the green threads term today to mean a much more featured version that is as you describe it. Lisp also has it. So really everyone is right, except for your statement that Lisp does not have green threads. It has native, old style green and new style green threads.