Hypothes.is reminds me a lot of some of the primary goals of the MeAggregator JISC project, as well as having a lot in common with other annotation tools (obviously!). The implementation appears smooth and reliable, and having just revisited it (thanks to a Facebook post by a friend of a friend), I wish I had been using it for a while now. I suspect it will be finding its way in to my teaching practice very soon.<br> This page on their site "Back to School with Annotation: 10 Ways to Annotate with Students" has some useful suggestions. I particularly need to check out the private groups and sharing options, and investigate the possibility of collating annotations (potentially producing new documents from a set of annotations).