Alan Kay:

The key in making great and growable systems is much more to design how its modules communicate rather than what their internal properties and behaviors should be. Think of the internet – to live, it (a) has to allow many different kinds of ideas and realizations that are beyond any single standard and (b) to allow varying degrees of safe interoperability between these ideas.

（要做一个伟大且不断生长的系统，关键与其说是规定每个模块内部该是什么、做什么，不如说是设计模块之间如何通信。想想互联网——它能活下来，是因为：(a) 它允许许多不同的想法和实现存在，而它们不必都被某一个统一的标准框死；(b) 它允许这些不同的想法之间，以不同程度安全地互通。）