The developer (Devel) module

On your development environment, you can install a handy module called Devel (http://drupal.org/project/devel), which provides several sophisticated tools designed to help developers create and debug Drupal code.

The following are a few of the features of this module:

• Functions used for dumping objects and arrays into formatted Drupal output
• Tools for analyzing database usage and performance
• A content generator for quickly populating your site with testing content