This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I believe the answer is that the abstract part is simply implied whether you write it or not. I wouldn't call it obsolete, just a shortcut. An interface is always abstract so it is not necessary to specify it as abstract. Think of an interface as an abstract class except an interface's methods are all abstract unlike an abstract class which may have non-abstract methods. [ December 16, 2004: Message edited by: J Williams ]