[drbawb]

Come to think of it, I do know some editors that support HTML rendering inside comment blocks.

How would you use it for coding, though? Unless you stripped it before the compile phase I would think any formatting in a rich-text format would choke up almost any interpreter or compiler.

[davidcuddeback]

It doesn't need to be rich text. It can just be the way the editor does syntax highlighting. Say, for example, underline all function names. The compiler won't know anything about this style and will therefor not choke on it.