RockMelt, a company backed by Netscape founder Marc Andreessen build a new browsing experience for sharing. You browse with your friends (the first thing you do is log into Facebook and your favorite friends and their latest status updates are always available along the left rail). And there's a big "Share" button up top, which lets you share any webpage, along with images and a preview, on Facebook. You could call it a Facebook browser, but it really is more than that.
The three biggest changes to the browser that you notice with RockMelt is that it is built around friends, feeds, and search results. The left rail is for friend. The right rail is for sites. And the top rail is for search.
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