Play Framework vs Meteor

It's like Java, but more Haskell-y.

Play has quite a large community which provides numerous tutorials and videos related to developing with Play.
The Play official documentation covers many things, such as the framework itself but also specific stuff such as Akka, SBT and Netty.

There are also many big companies that base their main sites around Play, one of them is LinkedIn which provides third-party documentation on a regular basis.

Play uses Akka for concurrency, Scala for a templating engine, Netty as a client-server framework and SBT (Simple Build Tool) for building. And they all come out of the box.
Play also comes with the option to scaffold your applications. Play is an all-embracing ecosystem designed to increase developer productivity and shorten development times.

Play is very simple to get started. The documentation is very helpful for beginners and advanced users alike and the official website has a great "Getting Started" tutorial to begin developing with Play.

Play framework's convention over configuration methodology makes most Play projects have a very similar structure. This means that the code written for the framework is very readable. This enables a developer to switch between applications without having to relearn the ecosystem for every project. The built-in templating system also helps with code and makes it possible to have a very low count of lines of code.

Java is one of the most widely known languages, so people coming from that background can jump right in and not have to learn a new language syntax.

Meteor was developed with simplicity in mind, even for beginners who have just started using JavaScript frameworks. One of the reasons that beginners should start with Meteor is that Meteor is a full-stack framework, this way they can get the complete learning experience when it comes to web development (back-end and front-end development), all by using a single platform and a single language.

Furthermore, Meteor does not have complex and esoteric concepts that may be hard to grasp by a beginner, it has a clear documentation and well-established coding conventions.

There's also a very useful resource for learning Meteor in the form of a book: Discover Meteor, by the authors of many Meteor packages.

Changes in the database will be propagated to all subscribed clients in real time, without you having to write any code.

A Meteor package can supply code for both the client and the server, and for mobile (Cordova) apps. For example, an autocomplete package supplies both server code to search a collection, and client code to display the results. The mdg:camera package supports the native camera if the app is built for mobile, or the HTML getUserMedia API to take pictures from the browser.

Meteor takes care of many concerns with it's out-of-the-box security measures.

Meteor is built on top of Node.js and jQuery on the client.

Meteor enables the client and server to communicate data seamlessly, in real-time. You don't have to write any REST API or pub/sub code - Meteor takes care of it all automatically for you.

Meteor uses both your existing front-end library and it's own library called Blaze, which is integrated beautifully in the framework and fulfills the purpose of a true MV* front-end framework.

Every time a change in the source file is saved, all connected clients will refresh automatically - browser tabs, mobile apps running in the simulator or on the physical device.

Or, deploy a Meteor app (meteor deploy myapp) and all clients, plus all mobile apps with the server set to myapp.meteor.com will automatically reload to use the code changes.

This drastically reduces the development cycle for apps in the App Store, where a regular update can wait for one to two weeks before being approved.

Meteor is the 10th most starred project on GitHub and has overtaken even Rails.

While Meteor only supports MongoDB and Redis natively, MySQL support is on the roadmap, and there are 3rd-party packages that integrate MySQL reactively with Meteor to some extent, such as numtel:mysql. For reactive PostgreSQL support, there is numtel:pg.

Meteor also has an official testing framework called Velocity. Velocity enables real-time unit testing and integration with Jasmine or Mocha syntax. Tests are automatically run when code is saved and the testing result is indicated by a green or red dot in the upper right corner of the app.

The client will mimic instant server-side response, and updates automatically if it was different once the information is available.

Meteor can generate mobile (iOS and Android) apps from the same codebase as the web app, using the Cordova (PhoneGap) library (which brings native device functionality to JavaScript applications).

Meteor-generated mobile apps are JavaScript, HTML and CSS bundles that run in a UIWebView (on iOS) or WebView (on Android). Apps can be run locally in the iOS/Android emulator, or on physical devices. You can also publish them to Google Play Store or Apple's App Store.

Moreover, these hybrid mobile apps benefit from hot code push, which dramatically accelerates the development cycle.

Meteor uses MongoDB, eliminating the choice among NoSQL databases. MongoDB is highly scalable - used to store petabytes of data and perform billions of operations daily at eBay, FIFA, Adobe, Craigslist, McAffee, Foursquare and others.

Although Meteor's server side runs on top of Node.js, it manages to avoid callbacks by making use of Fibers.

Meteor's package repository called Atmosphere has more than 5000 packages available. What's more is that Meteor can also use into the packages available for the Node ecosystem.

Meteor uses Kadira which is an excellent performance monitoring tool for Meteor apps. It profiles CPU and RAM consumption, subscription latency and throughput etc.

Bright future for Meteor - funded by venture capital and open-source.

The community behind Meteor has created a useful application for debugging Meteor apps that will automatically delete collections and display client-side documents, allow you to control subscriptions and lets you modify the documents.

Meteor also has great support for server-side debugging, and WebStorm has also released full support for Meteor, including debugging capabilities.