At the recent hackfest in Perth there was an interesting discussion on responsive design and how it could potentially be added to moodle's core themes. One of the difficulties is that there is a lack on consistency in how UI elements are created in Moodle, which makes it really hard for theme designers to ensure that all pages across the site are correctly styled. This lack of UI consistency also has an impact on overall usability.
In order to try to tackle this problem in our distribution of Moodle (called Totara) we've developed an "Element library" which we distribute with the code. It provides a set of linked pages with examples of common UI elements. It provides theme designers with a single place to go to check their themes and developers with commented examples, so they can see the best way to implement a particular UI element.
I demoed what we have at the hackfest and there was interest in integrating it into core Moodle, so I've created a bug and shared the code here:
If you're a theme designer or UI guru and you've got any interest in this concept, or you've got some ideas on how you'd like it to develop, or some time to help identify common UI elements to improve the library, I'd love to hear from you!