I don't care much for the style of David Mark's rhetoric, but he is not only one to criticize Sencha in that thread. While David doesn't manage to get his point

I don't care much for the style of David Mark's rhetoric, but he is not only one to criticize Sencha in that thread. While David doesn't manage to get his point across very effectively, let's consider some of popular JS libraries: Prototype.js: Messes with the prototype of all your objects, that can't be good. ExtJS: Big enterprisey clusterfuck, though the widgets look pretty good. jQuery: I do use jQuery but last time I browsed through its source I was appalled by all the dirty hacks. The plugin situation is an unmaintanable clusterfuck. The UI library is still lacking after years of development. I hope the popularity of node.js will drive the development of new and better JS libraries, because our current situation is unimpressive.