This is a quick explanation of Curvilinear Design, this page has been used as a handout in some of my design courses and has also been thrown up on a screen to help me make a point during a discussion of the design process.
Curvilinear is one half of the design story. Formal, or some may say straight line, right angles, or Geometric. In another way of looking at this you could go Geometric vs. Curvilinear, or Formal vs. Informal. And this discussion could go on for hours.