What was that sliding stacking side menu in Hacker News recently?

Found it! <a href="http://tympanus.net/Development/MultiLevelPushMenu/index2.html#" rel="nofollow">http:&#x2F;&#x2F;tympanus.net&#x2F;Development&#x2F;MultiLevelPushMenu&#x2F;index2.ht...</a>