I think thats not directly language related but an implementation detail - although a very important one. Javascript on the JVM (Nashorn) allows full multithrea

I think thats not directly language related but an implementation detail - although a very important one. Javascript on the JVM (Nashorn) allows full multithreading - including then the need for all the common synchronization stuff. But of course - Javascript and also the typical Javascript libraries were not made with multithreading in mind.