AgileDocumentation

On the other hand traditional projects often use a LOT of documentation.

My personal feeling is, that some documentation is helpfull, but I'm not exactly sure how that documentation would look like.

I would like to share ideas and experience about what is a helpfull documentation. How and when it can be created and maintained.

Also of interest would be auto-generated documentation. What is you experience? What tools do you use to document systems? Are there interesting ideas or tools to make an "undocumented" system more accessible due to auto-generated documentation? Are there interesting ideas or experience with annotation-systems that support auto-generated documentation but must be "built into" the software?