gistfile1.js

var Summary1 = React.createClass({
  render: function(() {
    var cards = this.props.cards

    return (
      <div>
        <Notification />
        <div>
          cards.map(function(card, i) {
            return <Card key={'key' + i} data={card}>
          })
        </div>
      </div>
    )
  })
})

var Summary2 = react.createClass({
  render: function() {
    return (
      <div>
        <Notification />
        <div>
          {this.props.children}
        </div>
      </div>
    )
  }
})

React.renderComponent(<Summary1 cards=[1,2,3,4] />, document.body)
// or ..
React.renderComponent(
  <Summary2>
    <Card data={1} />
    <Card data={2} />
    <Card data={3} />
    <Card data={4} />
  </Summary2>, document.body)

// never renderComponent into a DOM element alreadt owned by a another react app.