It should be plain to see that it would be much easier to implement your programming language on top of the CLR or JVM if you didn't need to request new feature

It should be plain to see that it would be much easier to implement your programming language on top of the CLR or JVM if you didn't need to request new features from Oracle or Microsoft to be added to the runtime. I remember one time someone proposed a patch to the JVM to add tail cail optimization and it was basically rejected or deprioritized into oblivion: http://mail.openjdk.java.net/pipermail/mlvm-dev/2010-October/002017.html http://mail.openjdk.java.net/pipermail/mlvm-dev/2010-October... These VMs are complicated machines and Oracle/Microsoft aren't going to risk modifying them unless it fits their respective agendas.