A close superset of ES7 with JSX and Flow, built with Babel. Designed to make programmers a little more productive. Item({ item, isActive, onClick }) => className = if isActive: 'active' else: 'inactive' <li onClick={onClick} className={className}> {item} </li> class List extends React.Component: activateItem(itemId): void => if this.state.activeItem == itemId: this.setState({ activeItem: null })