What is GWT?
The core idea in GWT is that you can write your user interface in a structured language with good tooling (i.e. Eclipse or Maven) and you can share code with your existing server-side implementation. The GWT community is very active with some 100 000 users every month.
What is Vaadin's relation to GWT?
As a Vaadin developer, it's not necessary for you to know about the existence of GWT. In fact, if you're using Vaadin or planning on using it, a much better resource for learning about Vaadin is vaadin.com/introduction.
GWT is a powerful technology that Vaadin utilizes and thus we want to see the GWT community thrive and to contribute back to it. Vaadin organizes the largest GWT conference in the world, GWT.create, and helps to market GWT. All the fixes we make to GWT in Vaadin contribute back upstream.
Vaadin and GWT
Vaadin's core utilizes GWT and heavily depends on it. Without GWT, Vaadin wouldn't be what it is today.
All bug fixes and features created for Vaadin or our support customers are automatically committed upstream back to the GWT core.
Vaadin is an active member in the GWT Steering Committee, helping steer the future of GWT.