if vaadin can also use boostrap that would be nice!

will this happen? i like valo. but is good to have both

Hi DiWen. While technically nothing prevents you from using Bootstrap for your Vaadin application, I believe it would be very cumbersome. But the real question is: what would you want to achieve by using Bootstrap? If you need responsive web design, there are means in Vaadin framework (see e.g. Responsive component extension).