How to become Vaadin contributor?

I use Vaadin for 3 past years and know many things about it internals. In my applications I use many hacks (I not found possible protected API for implement this) which may be carefully integrated in main stream project.
How to produce patches/ideas to Vaadin ? How to contribute ?

Which Vaadin version(s) are you interested in contributing code to? Vaadin 6 or 7?

The best place to start is to read
http://dev.vaadin.com/wiki/DevDocs/ContributingCode
and
http://dev.vaadin.com/wiki/DevDocs/StartingDevelopment
.

You’ll need to sign a contributor agreement before submitting code to Vaadin.

Ideas can be communicated as enhancement requests in the issue tracker, or discussed first on the forum.

Currently, the first phase for code contributions is submitting contributions as patches in tickets. Very often, at least the first patches go through some revisions, but if the quality is good, it’ll get easier to get future contributions in. Pay attention to the coding conventions and formatting configuration when making patches.

We are also trying to make contributing code to Vaadin 7 easier and quicker - more on that later when we make some progress with that.