[chubot]

I think it depends on what your expectations are.

From one perspective, it's a big success in that it's deployed "everywhere", has multiple implementations, and seems to work the same way everywhere. Many language toolchains target it, although there are varying degrees of success / performnance.

From another perspective, it's a "failure" because it's not the end of JavaScript, and it's not an operating system.

There were a number of people/organizations promoting as such -- saying it's basically going to take over all of computing, and be both the foundation of all languages and the foundation of operating systems. That seems a bit silly.