Integrating Bootstrap CSS with Vaadin (proof-of-concept). It does not try to bring Bootstrap JavaScript components/widgets to Vaadin. The goal is just to style Vaadin components to look like Bootstrap.
Using the default bootstrap.css as a base, and then using the default Sass compiler to extend Vaadin class names from the Bootstrap class names. The Vaadin Sass compiler throws a bunch of errors from the Bootstrap CSS at the time of writing, so another Sass compiler should be used instead (Ruby, LibSass, etc.)
Current progress can be seen here (can be out of date if I forget to update the demo after a commit):
http://jouni.app.fi/bootstrap/
This project is more or less just a stub which be built upon if you wish to use Bootstrap CSS, and I’m more than open for pull requests which style more components. Look inside the files in the css folder to see how the integration is done.
To update Bootstrap, replace the bootstrap.scss file in the vendor folder with the latest version of the compiled Bootstrap CSS (rename the file from .css to .scss so that Sass can import it correctly).