What's That Gizmo?

• Access is necessary

  "Buying proprietary software is like buying a car
  that has the hood welded shut". - Bob Young

  This is perfectly fine with most users, and may even
  seem like a good thing in many cases, but someone
  (i.e., the mechanic) will always need access.

• But not sufficient

  Software systems, like cars, may be getting simpler
  to use, but they certainly aren't getting simpler inside!

  To repair, customize, or improve complex systems,
  all engineers need good, detailed documentation.

  Otherwise, they cannot hope to function efficiently,
  let alone produce good results.