JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://github.com/downloads/SteveSanderson/knockout/knockout-2.1.0.js"></script>
<div data-bind="with: nested">

    <p>First name: <input type="text" data-bind="value: firstName, valueUpdate: 'afterkeydown'" /></p>
    <p>First name: <strong data-bind="text: firstName"></strong></p>
    <p>Last name: <strong data-bind="text: lastName"></strong></p>

</div>

JavaScript

function AppViewModel() {
    this.nested = new NestedViewModel();
}

function NestedViewModel() {
    this.firstName = ko.observable();
    this.lastName = "Bertington";
}

ko.applyBindings(new AppViewModel());