One year after it opened an incubator in San Francisco that offers free space to selected entrepreneurs, Polaris Venture Partners is bringing the concept to Cambridge. The Waltham VC firm is formally announcing Dog Patch Labs Cambridge tonight at a special event at Fenway Parks EMC Club  which will also mark the successful IPO this summer of LogMeIn, a Polaris-backed start-up.

The San Francisco version of Dog Patch (located at Pier 38 on that city's waterfront, left) was the brainchild of Mike Hirshland, a Polaris partner based in Waltham who focuses primarily on digital media companies. Hirshland describes it as a frat house for geeks that offers free desks, connectivity, coffee, and grub to entrepreneurs that the firm dubs interesting. Unlike a traditional incubator, theres no formal agreement that gives Polaris equity, or even a right-of-first-refusal on investing in any companies hatched at Dog Patch. But Polaris has put money into two West Coast ventures thus far: Thing Labs (formerly Plinky) and LOLapps.

Dog Patch Cambridge will be co-located with Allurent, a Polaris company that works on improving the e-commerce experience. Hirshland explains that the Lab will be a venue for dinners, brown bag lunch talks, workshops, and conferences - and itll also serve as a hang-out for Polaris partners visiting the big city from their usual perch atop Mount Money in Waltham. Part of Hirshlands plan is to create a bit of an exchange program between the Cambridge and San Francisco labs, so that entrepreneurs and Dog Patch Fellows (friends of the labs who may be experts on some topic, or more experienced entrepreneurs) can hop back and forth.

"The objective is to foster a vibrant community of entrepreneurs," Hirshland writes in an e-mail. "What we have to gain is being deeply immersed and engaged in the very early stage entrepreneurial ecosystem -- which we see as just an extension of what we are already doing every day..." Hirshland explains that Polaris doesn't "see [Dog Patch Labs] as a feeder system for Polaris investments -- though as it has worked out in SF that has been a nice side benefit."

Here's more about the new space: