heheh... not sure if you are joking, but in case you aren't, IMO stands for in-my-opinion. He's saying notepad works fine.
So far, I have found primal script and Zend studio to be the best. Maybe it'll offend a few, but you are a fool to use notepad as your editor. It can save tons of time and hair pulling using a program that color codes syntax. Zend does a great job of automatically highlighting what bracket you are in as well. They also provide easy organization of projects, and many other features. Dreamweaver is my 3rd choice for an editor, but still a good program.
Anyway, there is no reason to use notepad since there decent free programs available as well.