AngularJS has very many similarities with Knockout, except the templating vocabulary is completely extensible (you can create components by creating new HTML elements and modify behavior of existing elements using custom element attributes).

Also in contract to KnockoutJS, AngularJS doesn't require any special wrappers for your model (no ko.observable() all over the place), which means that it's less intrusive and allows you to create models the way you want them to be (need a native array, primitive or custom type? no problem).