Altmetrics refers to new ways of measuring the impact of scholarly work using social media and online references. This document discusses the emergence of altmetrics and tools for measuring the likes, shares, downloads and mentions of academic articles, datasets and other research outputs on platforms like Twitter, Facebook, blogs and more. It outlines services like ImpactStory, Altmetric.com and PlumX that provide altmetric data and profiles. While altmetrics give a more complete picture of impact, there is debate around whether online attention equates to quality and whether certain topics receive disproportionate attention online.