X1 is the brainchild of entrepreneur Bill Gross, who conceived and developed a similar product, called Lotus Magellan in 1989. Bill Gross is the founder of Idealab, a company that incubates Internet startups such as X1. Idealab founded Overture, which of course was acquired by Yahoo in 2003.
When Yahoo! released their desktop search product, I was a little concerned over the fate of X1. But X1 developers continue to impress and and X1 remains one of my my favorite desktop search tool. No desktop search tool comes close when it comes to file preview (Contextual previews). X1 has practically support for every filetypes that I have encountered so far. It can even show Adobe Illustrator drawings with the Illustrator program. X1 displays search results in their native format without requiring users to open the application it was created in - or even have it installed. With each new keystroke, results are displayed and refined immediately with search terms highlighted in contrasting colors
X1 5.0 was a major upgrade with a new, more standard, interface; an integrated index, allowing a single search across all of your data; huge performance improvements, no limits on the amount of data that can be indexed, tighter integration with Outlook; support for Thunderbird (and coming support for Lotus Notes). X1 fulfilled the promise in their latest release 5.2.
Enterprise Users with privacy concerns can consider the X1 enterprise edition. For beginners, X1.com has tutorial, a printable Quick Start Guide and excellent customer support alongwith very active user forums (They even have a RSS Feed for X1 Forums)
