The GNAT Programming Studio (GPS) is a cutting-edge Free Software IDE that
streamlines the interaction between developers and their software.  With its
intuitive interface, GPS is easy to use, simplying source navigation and
highlighting fundamental ideas in the program.

Features                          Tools
  * Developer-friendly              * Language-sensitive editor
  * Multi-language                  * Version control
  * Multi-platform                  * Graphical debugger
  * Modern GUI                      * Automatic code fixing
  * Multiple document interface     * Graphs (call, dependencies, entities)
  * Customizable                    * Application builder
  * Extensible tool integration     * Visual file comparison
  * Free Software                   * Source code reformatting
                                    * Automatic body file generation
                                    * intelligent source code navigation
                                    * Project Explorer
                                    * Project Wizard

WWW: http://www.adacore.com/home/products/gnatpro/toolsuite/gps/