Daniel Kudwien (aka sun on drupal.org and tha_sun on IRC) of Unleashed Mind is a prolific Drupal contributed module author, but also Drupal core developer.

He discusses some of the well-known modules that he helped author and maintain, such as WYSIWYG, Admininstration Menu, Image Assist, Inline, and Demonstration Site.

He's taken it upon himself to make sure a lot of the Drupal 7 APIs have been standardized and cleaned up as much as possible, and also rallied a lot of help on tackling Drupal's oldest standing task of "Node 8," which is allowing users to cancel their own accounts. Sun also gave a heroic effort on helping on many of the different exception patches during the code slush period, and fellow developer chx commenting that he's never seen anyone sprint for Drupal.