Editors and word processors are personal things. Some people like command line editors like vi and others hate them. Some people want a GUI but want it to just sort of sit there, others want bells and whistles.
I like online editors because I use a lot of different computers. I tend to store text documents and source code on-line. That way it doesn't matter where I am, I always have my documents and source code available to me (as long as I have an internet connection).
Here are a few different editors (all available online) for you to try. I've run into quite a few editors (amongst other sites) that require MSIE. All of the links below will work with Firefox.
Big Huge Labs Writer - Nice, clean editor. Keyboard short cuts. Auto save. Simple, elegant. Distraction free writing.
Edit Pad - Very bare bones. Blank screen. Just start typing. If easy and free is your type, this is your editor.
Google Docs - Full featres, MS Office compatible, word processer. All the bells and whistles. Now with offline support.
Dark Copy - Another distraction free editor. Small area or full screen.
JavaScript VI - It doesn't get any more painful than this. If you hate VI, do not click this link. If you love VI, now you can access it from any computer.
