I/O Ventures, one of the newest of the new breed of start-up incubators, is opening its application window for its second class — after a successful first round that saw its six fledgling companies all get funded or acquired.

The program is modeled loosely after YCombinator, an incubation program that started in 2005, that has shown it’s possible to give startup founders a small amount of cash, mentorship, and introductions, which in a period of months helps founders launch quickly. YCombinator’s list of alumnae include DropBox, Heroku, Reddit, and Scribd, and getting chosen is considered akin to getting a golden ticket to Willie Wonka’s candy factory.

I/O Ventures was founded in 2010 by four entrepreneurs, including founders of MySpace, BitTorrent, Lefora and HotorNot.com, ensconces its portfolio companies in its hip digs in San Francisco’s Mission District, providing mentorship and office space, in return for a small percentage of equity.

Its first class’s demo day to investors and the press earlier this year was surprisingly good. The six companies ranged from Skyara — a service intended to help people be more active in their city by being a marketplace for cool experiences — to Appbistro — a company that creates app marketplaces for companies that want their software to be built on by developers.

One I/O venture company, Damn the Radio, helps musical artists grow their fanbase inside Facebook, has already been acquired by Fanbridge. SocialVision has also been acquired, while AppRats, Anomaly, and AppBistro have all raised more than $400,000 each in funding.

Those are stellar results for a freshman class for an incubator. That’s true even in the current climate where there’s a huge interest and lots of competition to invest in Silicon Valley startups, following the stunning valuations for companies like Twitter, Groupon and Facebook.

Would-be I/O Venture companies need to apply by February 21, and classes start March 15.

I/O Venture companies get office space in the hip environs of the Summit Café in San Francisco’s Mission district. TastingSF