Best app server for Vaadin in 2015?

Is there a best app server for getting started on a new Vaadin project? Any to avoid?



Tomcat is a plain servlet container, so
it don’t help you much with other than Vaadin UI layer running there
. Naturally, if you base your app on Spring, Tomcat (or Jetty) is a fine choise, but otherwise I’d go with TomEE (based on Tomcat) if you are a Tomcat fan. Else I’d go with WildFly. It is Java EE 7 sertified, and generally moves really fast with modern technologies, has a great modern web server with good WebSocket support.

But practically any modern Java server should do just fine. The part where the largest differences are is in push support.