Tools used, in no particular order
Ant - Made the development process a million times easier.
Java - The language used, couldn't do much without it.
Stylus Studio - The best XML editor out there. Used to preview XSL transformations and anything XML-like.
JUnit - Used to unit test parts of the code. Essential to ensure the code's behaving right.
The GIMP - Probably the best free graphics program out there. Highly recommended!
SSH Secure Shell - A stable, reliable SSH client.
Microsoft Visio - Used to produce the UML. Flows better than its stuttery Java equivalants.
Tortoise CVS - A great CVS client that makes Windows Explorer an easy to use CVS environment.
Eclipse - The King of the IDE's where all the code was produced.