JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://dev.sencha.com/deploy/ext-4.0.0/bootstrap.js"></script>
<div id="placeholder"></div>

JavaScript

Ext.define('Ext.ux.Bootstrap',{
  extend: "Ext.util.Observable",
  constructor: function(c) {
     this.addEvents( 'ready' );
     this.initConfig(c);
     this.callParent(arguments);
     this.initialize();
  },
  initialize: Ext.emptyFn
});

Ext.define('Ext.ux.SimpleBootstrap',{
  extend: "Ext.ux.Bootstrap",
  initialize: function() {
    this.fireEvent('ready',this);
  }
});

Ext.create('Ext.ux.SimpleBootstrap',{
  listeners: {
    ready: function(bootstrap) {
        Ext.create('Ext.panel.Panel', {
    title: 'Hello',
    width: 200,
    html: '<p>World!</p>',
    renderTo: Ext.getBody()
});
      Ext.get('placeholder').update('Bootstrap is ready!');
    }
  }
});