[Raynos]

In all javascript apps the part that is slow is the DOM, not the javascript interface.

This benchmark was taken from the webkit source code then forked into http://vuejs.org/perf/ then forked to include mercury then forked again to include elm.

Neither elm nor mercury came up with this benchmark and just added themself to it.

What this benchmarks shows is that async rendering is really fast. Mercury, vue & elm all use async rendering where DOM effects are batched and only applied once.

A better, close to real user experience benchmark would be one using mousemove since that's an event that can happen multiple times per frame.

[loz220]

There is interaction occurring with the DOM in both benchmarks.

The way that the Backbone TodoView is designed does not take into account the possibility of a user adding 100 items using the dom within a tight loop. Probably because such a use case is impossible outside of this type of benchmark. By doing so the Backbone implementation ends up performing a lot of unnecessary renders. Therefore as far as Backbone performance is concerned this benchmark is not indicative of any real world scenario.

Just to re-iterate; when you're loading a set of todos from your local storage to display when the user first opens the page, you would not populate the "new todo" input box and fake an enter event for each item that you want to add. Instead you would reset the Backbone.Collection with a list of your new todos (go through the interface). That's basically the change I made to the benchmark. Sorry if it wasn't clear.

[jbish]

Running your perf test, I consistently get Backbone being the fastest, Angular the slowest, and the projects using Virtual DOM approach somewhere in the middle. Is that expected? http://evancz.github.io/todomvc-perf-comparison/

edit: I was running the original test instead of your fork.