Drupal Developer: http://drupaldeveloper.in

Drupal Developer guides developers in developing and customizing Drupal modules and themes. Drupal Developer is a comprehensive guide to learn Drupal by Developing modules and themes. This site offers great tutorials about Drupal API, module and theme development with examples of implementation. A section called CodeBook is a collection of CodeLets of a kind. These CodeLets are from some of the live sites which are tested for consistency and security. The site features facebook connect, twitter integration and facebook like status updates. Users can invite their friends and can earn some points. Users are highly motivated to share their codes by creating their own CodeBooks and ThemeBooks. All the CodLets and contents are published under GNU/GPL license.