Jason of 37signals:
Software needs an editor like a writer needs an editor or a museum needs a curator. Someone with a critical eye and the ability to say “No, that doesn’t belong” or “There’s a better way to say this.” Physical constraints create natural limits for books and museums. Books have pages and museums have wall space. Software, on the other hand, is virtual, boundless. Anything is possible. When anything is possible someone inevitably tries to make something do everything. And the more something does the harder it becomes to understand, grasp, and use. So the key is deciding what makes it and what doesn’t.
This is what defines great software: great design and great editing.