JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cloud.github.com/downloads/SteveSanderson/knockout/knockout-2.0.0.js"></script>
<div id="block1">
    <h1>Block 1</h1>
    <p data-bind="text: message"></p>
</div>
<hr />
<div id="block2" data-bind="visible: true">
    <h1>Block 2</h1>
        <p data-bind="text: message"></p>
</div>

JavaScript

window.IsViewModelReady = ko.observable();

var viewModel = function(prefix) {
    var self = this;
    self.message = prefix + " Hello world";
}
    
ko.applyBindings(new viewModel("Block 1"), document.getElementById('block1'));
setTimeout(function() {
    ko.applyBindings(new viewModel("Block 2"), document.getElementById('block2'));
}, 2000);