React Base Fiddle (JSX)

Starting point for creating JSFiddles with React. This uses React with Addons.

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.1/JSXTransformer.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.1/react-with-addons.js"></script>
<script src="https://facebook.github.io/react/js/jsfiddle-integration.js"></script>

<div id="container">
    <!-- This element's contents will be replaced with your component. -->
</div>

CSS

.c { background: yellow }

td { border: 1px solid gray }

table { border-collapse: collapse }

JavaScript 1.7

var ROWSC = 400;
var COLSC = 100;

var Hello = React.createClass({
	getInitialState: function () {
        return {
            t: { "1-1": 'c' }
        };
    },
    clicked: function (k) {
    	var t = this.state.t;
        t[k] = t[k] ? 0 : 'c';
    	this.setState({  t: t  });
    },
    render: function() {
    	var items = [];
        for (var r = 0; r < ROWSC; r++) {
	    	var cols = [];
	        for (var c = 0; c < COLSC; c++) {
            	var k  = ''+r+'-'+c;
    	        cols.push(<td key={c} onClick={this.clicked.bind(this,k)} className={this.state.t[k]}>&nbsp;</td>);
	        }
            items.push(<tr key={r}>{cols}</tr>);
        }
        return <div>Hello {this.props.name}
        	<table>
            {items}
            </table>
        </div>;
    }
});

console.time('a');
React.render(<Hello name="World" />, document.getElementById('container'));

console.timeEnd('a');