TagCloud is an automated Folksonomy tool. Essentially, TagCloud searches any number of RSS feeds you specify, extracts keywords from the content and lists them according to prevalence within the RSS feeds.
D. Skoutas, und M. Alrifai. In Proc. of 20th ACM international conference on Information and knowledge management (CIKM '11), ACM, New York, NY, USA, 221-230., (2011)