The Meteor is a full-stack open source framework to create Web, Mobile, and Desktop applications.
Only one language in back and front is great, but to can create a Web, Mobile and Desktop application with the same code base is awesome. With Meteor, you can save time, and money of course.
Despite using the same language, client and server can be decoupled. Meteor has an own communicate protocol between client and server, the DDP (Data Distribute Protocol). It gives a lot of goods to developers, as a default reactivity of data from database (MongoDB). DDP works inside a Web socket, then you can connect to it using any language which support Web socket.
An important variable to define how useful a framework can be, is how many and how good are its tools (libs). How about using any NPM Package? Yes, you can import any NPM package to front or backend. The power of this is infinite.
I've been working with many languages and frameworks along my professional life, and I ever hate lost hours or days to set up my development environment. It doesn't make sense. Meteor can be installed in Windows, Linux, and Mac using just one command line of NPM (you need NodeJS installed, of course, that is simple to install too). After Meteor installed, you just need to start your application.
To deploy, you have some directions to follow: use a specific Meteor host (Meteor Cloud/Galaxy, Scalingo, NodeChef); use a NodeJS host; create your own server (Docker, Meteor-Up, Passenger). The first way has many advantages and are good for beginners. They usually have free tier to tests.
The documentation is huge, and the community is active. There are tutorials for each type of frontend technology you want to test. Meteor support the most used frontend frameworks (React, Vue, Blaze, Svelte and Angular).