SAN JOSE — Every sixth Saturday or so, dozens of young software developers flock to a small mansion somewhere in Silicon Valley to share technical tips, collaborate on the coding of pet projects, and knock back a few beers while debating the data-models underlying popular startups like Facebook and Twitter.

This informal gathering that's open to the public flows from 2 p.m. to 2 a.m. with free alcohol, energy drinks and innovative ideas. It's a tech party known as SuperHappyDevHouse, and it's lured rank-and-file employees of Google, Oracle and still-nameless endeavors.

It's this robust swapping of ideas and sharing tricks-of-the-trade across company lines that has given Silicon Valley an innovative edge since the '70s.

DevHouse has codified that collaborative culture for a new generation of inventors.

DevHouse organizers say they're trying to "resurrect the spirit of the Homebrew Computer Club," the legendary '70s garage gathering of hobbyists Steve Jobs, Steve Wozniak and other founders of computer companies.

Throngs of techies

Today's reincarnation, which has been attracting throngs of techies by word of mouth for two years, bills itself as "a party for hackers and thinkers." It's a haven for passionate programmers who modify software with creative and sometimes kooky code, as opposed to crackers who break into computer systems.

This 12-hour programming party was the brainchild of now 21-year-old Web developer Jeff Lindsay, who bypassed college because he was eager to tackle real-world tech problems rather than sit in classrooms solving problem sets.

While Silicon Valley is cluttered with tech clubs, DevHouse is unique in that attendees churn out technical projects rather than just swap business cards.

Its most successful creation has been PBwiki, an online template for creating Wikipedia-type collaboration Web sites. It received $2 million from Mohr Davidow Ventures in February.

Lindsay said Microsoft offered to host the party at its Mountain View campus, but he turned it down: Working in walled-off cubicles would ruin the fun, collaborative atmosphere.

But DevHouse did recently accept a food fund from Mohr Davidow Ventures that covers the $500 tab each party racks up buying beer, Red Bull and snacks to fuel the programmers through the night.

At the party expect to see more than five men for every woman. Most are in their 20s and 30s, although a teenage girl has shown up as well as a man with a full head of gray hair.

Hackers hailing from as far away as Dublin, Ireland, plunk their laptops down at DevHouse when they're in town on vacations or business trips. Some of the regulars relocated here from places like Lexington, Ky., and Pittsburgh.

"I moved down here because of stuff like this," said Matt Rubens, a 25-year-old software engineer who worked at Amazon.com and then established a startup in Seattle. He ditched that in April for Silicon Valley's scene.

A typical party

The last SuperHappyDevHouse, also known as SHDH, drew about 95 people who swung by for various stages of the 12-hour event. Here's how the party played out on May 5:

2:15 p.m., study hall: Sixteen programmers quietly clack on their laptops while sitting on plush couches that have been pushed against the family room walls so there's more floor space where later arrivals can sit.

Barbara Harrison, whose 25-year-old live-in son, Tom, is hosting this SHDH, has been in the kitchen cooking since 4 a.m., and she's still at it, checking on the casserole and whipping up Rice Krispie treats.

3:28 p.m., syncing up: Three laptop-toting strangers sitting around a table on the sun deck strike up a conversation about quiblz.com, a social-networking polling startup that is in test mode.

"How are you planning on monetizing it?" asks Sven Strohband, a 33-year-old partner at Mohr Davidow Ventures.

9:11 p.m., lightning lectures: A white king-size bed sheet hangs over the living room window as a makeshift projector screen for the night's six-minute technical talks. More than 50 people cram onto the couches and carpet, lean against the walls, and strain to hear from the hallway during the 1 1/2 hours of programming presentations.

11 p.m., the hot tub: Seven or so partyers unwind in the outdoor pool and hot tub, giving their brains a break from the buzz. After an hour or so, they towel off.

"Longer than that, and I risk my fingers over-pruning," wisecracks 23-year-old electrical engineer Mike Lundy, "and that would make it hard to type."

2:05 a.m., coffee to go: Barbara Harrison turns off the music and announces it's time to clean up. She offers coffee that the remaining 35 late-nighters can drink now or take in to-go cups.

After 75 minutes of tidying up, the Harrisons are ready for bed. Others don't want to call it quits. Six wide-eyed hackers — including SHDH co-founder Lindsay — hop in their cars so they an continue discussing action scripts, Twitter adapters and theoretical Web services at Denny's.