I am slightly surprised that 9 people have downvoted On Interfaces and APIs

Either they are extremely good at interface design or they fail to see the wisdom of the content. I strongly suspect the latter as I see very few examples of excellent (web) interface design. It's something I look for as I am writing a book on the subject to help business owners find, brief and manage web designers so that the result is a website that serves the business needs more than the designer's ego.