Is o_O the best HTML binding library out there?

It certainly shares some features such as data-bind.

But it's much smaller and simpler. It's also general purpose rather than the Root style for Knockout.

Additionally it uses jQuery to deliver most of the bindings which makes it one less thing to learn.

It looks like the primary difference is that Knockout has a no-dependency philosophy while this library is explicitly designed to be used with other libraries.