UI漂亮的例子
https://google.github.io/closure-library/source/closure/goog/demos/hsvapalette.html
https://google.github.io/closure-library/source/closure/goog/demos/dimensionpicker.html
https://google.github.io/closure-library/source/closure/goog/demos/menubar.html
https://google.github.io/closure-library/source/closure/goog/demos/colormenubutton.html
https://google.github.io/closure-library/source/closure/goog/demos/inputdatepicker.html
https://google.github.io/closure-library/source/closure/goog/demos/menubutton.html
https://google.github.io/closure-library/source/closure/goog/demos/editor/editor.html
https://google.github.io/closure-library/source/closure/goog/demos/jsonprettyprinter.html
https://google.github.io/closure-library/source/closure/goog/demos/progressbar.html
https://google.github.io/closure-library/source/closure/goog/demos/quadtree.html
https://google.github.io/closure-library/source/closure/goog/demos/useragent.html

项目历史与开发者社区
我不知道Google Closure内部用了多久，应该很久吧（以Gmail 05启动开始算）。Ext 大概06年在研发，到现在应该也为数不少人开发人群了吧，有数字透露是500,000 developers