Prism is the coolest idea I have come across in a long time. Coming from the University of Virginia Scholar’s Lab, Prism is a collaborative interpretation environment. Someone comes up with categories like “Rhetoric”, “Orientalism” and “Social Darwinism” for a text like Notes on the State of Virginia. Then people (with accounts, which you can get freely) go through and mark passages. This creates overlapping interpretative markup of the sort you used to get with COCOA in TACT, but unlike TACT, many people can do the interpretation – it can be crowdsourced.
They are planning some visualizations of the results including what look like the types of visualizations that TACT gave where you can see words distributed over tagged areas.
Bethany Nowviskie explains the background to the project in this Scholar’s Lab post.