An essential tool in my day-to-day writing is a thesaurus, and I've tried countless computerized versions. I was once a fan of Princeton's WordNet, but its knotty interface finally drove me away. I was pleased to find that Nisus Thesaurus used the extensive WordNet data, which I still really liked, but I could never figure out why its results were so much more limited and less rewarding than the original.
Still attached to the rich linguistic mine of WordNet, I next turned to Visual Thesaurus. I leeched off the free web-based interface for a while, then finally committed to the desktop app and never looked back. It is truly delightful to use; its engaging interface encourages exploration and results in many serendipitous events. That's exactly why you turn to a thesaurus in the first place, and the Visual Thesaurus is a keen example of how good computer-based reference materials can be when they break free of their paper-derived chains.
This week Visual Thesaurus 3.0 debuts, with some very nice additions. But it is all new to you if you've never tried it, so I won't bore you with a bullet list of the changes. Instead, go see if it is all that I've claimed it to be. Take the screenshot tour, or better yet, try out the Java-embedded version and experience it for yourself. If you're interested in language, hypertext, visual design, or user interface design, I think you'll find it worthy of your attention.