For Mac researchers wanting a tool to integrate "visual arts, design and theoretical research," check out txtkit (via Ulises Mejias):

txtkit is an Open Source visual text mining tool for exploring large amounts of multilingual texts. It's a multiuser-application which mainly focuses on the process of reading and reasoning as a series of decisions and events. To expand this single perspective activity txtkit collects all of the users mining data and uses them to create content recommendations through collaborative filtering. The software requires Mac OS X 10.3 and Internet access.