Play Framework vs FeathersJS

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.

Feather can sync events happening in two different Node processes or even servers in real-time. For example: an event happens in server A, the user connected to server B is instantly notified of that event.

This is done through a central Redis or Mongo collection or through a websocket libraries' clustering library.

Through services, Feathers provides instant CRUD functionality, it also can easily expose a RESTful and real-time API through HTTP/HTTPS and websockets.

Since Feathers itself is built on top of Express (it's a thin wrapper over socket.io, primus and Express) and because of Feathers' highly modular nature, it's very easy to integrate Feathers in an existing Express project.

Feathers makes extensive use of modules (which are called Feathers services). These services work like ExpressJS middleware and can be used with app.use('/path', serviceObject).

Services help developers keep their applications modular and as minimal as possible, without any unnecessary libraries or bloat.

FeatherJS uses primus which is a universal wrapper for real-time frameworks. Through primus you can easily choose which socket transport you want to use.