LordPretender

With this class (singleton), you will be able to do a lot of things with your categories. 
There is a lot of methods available to do what you need, what you want to do.
If a method is missing, thanks to tell me and I will add it, if possible.

Category class

Here is a library for developpers which help them to use categories and posts whithin a simple class.

romainguillaume

This is a dashboard widget that uses AJAX to avoid load time excess. It displays the total and detailed estimations of bytes produced by each developers plugins and themes.

About Coder

Estimates the work of programmers who contribute to develop your Wordpress website plugins and themes.

Category class vs About Coder