用什么东西来形容美国文化会比较贴切呢?（English only）

The American culture is like open source community。It is different from traditional close software,which is only developped by one company。The open source community consists of many many developpers from differnt countries,and produces various flexible and wonderful softwares。The American culture is such a thing,formed by various cultures。Different immigrants from different countries have their unique culture,but form a new complicated and united American culture。Compared to close software,the American culture is not developped by only one group of people。