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
It is a little world See how many a pretty thing I always from the cube can bring: Chair and sofa, bench and table, Desk to write at when I’m able, All the household furniture, Even baby’s bed I’m sure; Not a few such things I see; Stove and sideboard here can be. Many things, both old and new, My dear cube brings into view; So my cube much pleases me, Because through it so much I see. It is a little world. Ellen Lupton & J. Abbott Miller, The ABC's of ▲■●: The Bauhaus and Design Theory Cubed modularity