Linga is a hypertext tool which combines comment threads, wikis, and bookmarking. Basically, in using linga members are able to create wikis for whatever webpage they're interested in and add comments, links to other pages, and information from different sources. The browser plug-in allows you to automatically bookmark pages as you surf the web. The wiki options include headers, bulleted links, fonts, and there's a syntax ledger as well. Each wiki entry is logged, so changes can be tracked. You don't need an account to view Linga wikis, however editing and commenting in the wikis do require registration.