What is Meteor?

Is Meteor a framework not a build tool only?

I have found a great table from 5 years ago: https://gist.github.com/ilyaigpetrov/afb50eb4060bc198de97

The number of features suggests that it can bear the proud name of

front-end agnostic isomorphic framework with a powerful built-in build tool and great JS community

How would you label Meteor in one sentence?


In one tutorial I have found a suggestion that Meteor is actually an API connecting all parts of packages together. Is it correct representation?