Hypothes.is is an open annotation tool for the web, allowing anyone to highlight, annotate, or comment on any webpage via a Chrome plugin (web developers can also install it on their sites, like I have with my blog).
Source: Hypothes.is as a public research notebook
It strikes me that blogging has always been an annotation tool for the web.
from Frank McPherson’s Web Notes http://bit.ly/2YPq44t
via IFTTT
Notes From The Cave 