Hi, there's a lot of tools for Joomla.
Joomla support for Eclipse, as a set of specific extension to PHPEclipse that are aware of Joomla framework specifics, and libraries. http://wiki.eclipse.org/Summer_of_Code
http://joomlacode.org/gf/project/jcode/frs/ -- http://joomlacode.org/gf/project/jcode/
PHP Development Studio Pro with Joomla included -- http://extensions.joomla.org/component/option,com_mtree/task,viewlink/li...
YouCMSAndBlog -Joomla WYSIWYG & Code Coloring IDE -- http://extensions.joomla.org/component/option,com_mtree/task,viewlink/li...
http://www.joomlaratings.com/content/view/570/66/ -- Joomla Developer support Tool - Class Creator
Hopefully that could inspire some ideas for what Drupal needs.