Everyone knows of the old adage that the best programmers can be orders of magnitude better than the average. I've personally seen good code and programmers, but never something so absurd. So the questions is, what is the most impressive feat of programming you ever witnessed or heard of?

You can define impressive by:

1. The scope of the task at hand e.g. John single handedly developed the framework for his company, a work comparable in scope to what the other 200 employed were doing combined.

2. Speed e.g. Stu programmed an entire real time multi-tasking app OS on an weekened including its own C compiler and shell command line tools

3. Complexity e.g. Jane rearchitected our entire 10 millon LOC app to work in a cluster of servers. And she did it in an afternoon.

4. Quality e.g. Charles's code had a rate of defects per LOC 100 times lesser than the company average. Furthermore he code was clean and understandable by all.

Obviously, the more of these characteristics combined, and the more extreme each of them, the more impressive is the feat.

So, let me have it. What's the most absurd feat you can recount? Please provide as much detail as possible and try to avoid urban legends or exaggerations. Post only what you can actually vouch for.

Bonus questions:

1. Was the herculean task a one-of, or did the individual regularly amazed people?
2. How do you explain such impressive performance?
3. How was the programmer recognized for such awesome work?