Designing .NET Class Libraries: Designing Progressive APIs

I found this lecture interesting.

http://msdn.microsoft.com/netframework/programming/classlibraries/designingprogressiveAPIs/

Favorite parts:

OO design methodologies are not good for API design. It should be started not in Visio, but by writing samples.

Aggregate components. This means that for particular task we can define particular component as part of bigger one. Like StreamReader can be part of file. Once all options of file is set all we need is to read data.

API should be progressive. This means new user should be able to use it, and while he is becoming more advanced, he will discover new features.

And classification of programmers is funny.