From <a href="https://groups.google.com/forum/#!msg/vertx/xgGgQcDeX04/0q8C1pylFaAJ" rel="nofollow">https://groups.google.com/forum/#!msg/vertx/xgGgQcDeX04/0q8C...</a><p>Here are some of the highlights of Vert.x 3:<p><pre><code> * A new and improved core API providing HTTP, SSL, TCP, UDP, DNS, WebSockets, File System, Event Bus, distributed maps, clustered locks, clustered counters and many more features
* Introducing Vert.x-Web http://vertx.io/docs/#web - a new toolkit for creating any type of web application from traditional server rendered apps, to modern client rendered apps, real-time apps, REST apps and HTTP micro services.
* Pluggable authentication/authorisation with out of the box implementations using JDBC, MongoDB, JWT and Shiro
* Pluggable metrics with an out of the box implementation using DropWizard metrics
* Database connectivity for MongoDB, Redis and JDBC
* Integration with SMTP mail and a JCA adaptor for interop with JavaEE app servers (e.g. WildFly)
* RxJava style APIs if you don't like callbacks
* Reactive Streams implementation http://www.reactive-streams.org/ for interop with other reactive systems (e.g. Akka)
* Introducing Vertx-Unit - a test toolkit for writing async tests
* Codegen of Java APIs into idiomatic APIs in other languages - including JavaScript, Ruby and Groovy
* Completely embeddable
* Simpler classloading model
* Docker images and support for Red Hat OpenShift
* Faster than ever</code></pre>