Name: WpPDE
License: GPL2
Website: http://wordpress.org/extend/plugins/wp-pde
Screenshots: http://wordpress.org/extend/plugins/wp-pde/screenshots/
Plugin Site: http://wp-pde.jaliansystems.com
WpPDE is a plugin development environment for WordPress. It allows you to create and maintain multiple plugins within WordPress itself. WpPDE includes an integrated editor (ace.ajax.org) for PHP code and a form editor for creating widget forms. There is online help within the plugin itself and more detailed documentation at the plugin site.
Please take a look and give feedback.