It is called Timeline js and it contains periods and actions for them and also allows the addition of videos and picture for a given period.
The idea is hidden in to the HTML classes:
TimelineContainer – time line.
timelineMajor – all html elements for an year
timelineMajorMarker – name of the year
timelineMinor – the action in the year
<dt id=”event01″><a>Event</a></dt> – Event for the action
<dd class=”timelineEvent” id=”event01EX” style=”display: none; “> – Event content
The vertical align in Chrome is not working so use this: