It’s been over a year since we first heard about RockMelt’s plan to enter the increasingly competitive browser market with an alternative that heavily focuses on social network integration – particularly Facebook. Although the idea is certainly not new (think Flock), the fact that browser pioneer Marc Andreessen of Netscape fame is backing it has helped RockMelt garner a lot of attention around the web as it launched in limited beta today.

The new browser is based on Chromium, so it inherits Google Chrome’s looks, feel and basic functionality, except with two thin rails down the edge of each side that incorporate Facebook and Twitter friends as well as other social features. You’ll be able to check your Facebook feed, share links and chat with friends, manage multiple Twitter accounts, add RSS feeds from your favorite sites, and even shorten URL links using RockMelt’s own service.

The search box at the top loads up a list of results in a drop-down menu, and begins preloading all of them so that you can flip back and forth between individual results faster. To be honest, one of the reasons I switched to Chrome is for its streamlined interface and speed, so I’m not sure I would want to clutter my browser with social networking features and the like. That said, it might attract hardcore social-media users and serious multi-taskers.

As mentioned earlier, RockMelt is currently in a testing phase but is accepting invitation requests through a Facebook connection for both Mac and Windows users. The company will reportedly be sending out download links as quickly as it can manage on a first-come, first-served basis.