So my pal is totally into videogames (level design, that is), so he got me into Fallout 3, so I browsed the web for modding resources, which get me to the official wiki of the official mod editor, the Garden of Eden Creation Kit.
Paint.NET is cited in the Mod Tools section of the wiki, and even have its own page, which I think is totally cool!!!
So thank you Rick, thank you Dean Ashton and all the folks for being so awesome !!