Meteor is an open-source, full-stack JavaScript platform for developing modern web and mobile applications. It is designed to make the process of building apps easy and efficient, allowing developers to quickly build apps with a minimum of fuss. Meteor combines powerful APIs and services with a flexible, reactive programming model, allowing developers to quickly and easily create powerful, real-time applications. Meteor's core features include a powerful real-time reactive data layer, an extensive library of packages for common tasks, and its own custom database system. Meteor apps can be built for any platform, including web, iOS, and Android, and can be deployed on any server or cloud infrastructure. Meteor is backed by a vibrant community of developers from around the world, who are constantly working to make the platform better.
It just works, compared to Meteor.
Meteor es full stack, Polymer is Front.
Firebase is a stack of tools / protocols for communicating with mobile applications. Meteor is a web framework. Apart from the fact that both are used by developers, they have nothing in common.