Designer, implementor, user, writer A Fragment by Donald Knuth dl.acm.org Thus, I came to the conclusion that the designer of a new system must not only be the implementor and the first large-scale user; the designer should also write the first user manual. The separation of any of these four components would have hurt TeX significantly. If I had not participated fully in all these activities, literally hundreds of improvements would never have been made, because I would never have thought of them or perceived why they were important. Eating your own dog food making
Essential vs. nice to have Customers have trouble distinguishing between essential features and those that are just "nice to have." Examples of the latter class: those arbitrarily overlapping windows suggested by the uncritically but widely adopted desktop metaphor; and fancy icons decorating the screen display, such as antique mailboxes and garbage cans that are further enhanced by the visible movement of selected items toward their ultimate destination. These details are cute but not essential, and they have a hidden cost. / Increased complexity results in large part from our recent penchant for friendly user interaction. I've already mentioned windows and icons; color, gray-scales, shadows, pop-ups, pictures, and all kinds of gadgets can easily be added. Niklaus Wirth, A Plea for Lean Software Menus, Metaphors and Materials: Milestones of User Interface Designlittlebigdetails interfacesux