It was 14 hours after the start of the PennApps Hackathon at the Wells Fargo Center and Max Bareiss, a student at Rowan University, showed no sign of fatigue as he bent over his laptop churning out computer code.

He and fellow Rowan students Nick Felker and Christopher Frederickson were hard at work Saturday, trying to develop a computer application clever enough to snag some of the more than $30,000 in prize money provided by event sponsors.

Their idea: an app to monitor pets for signs of injury, remotely alerting owners to problems by text.

"We are using the motion of the animal" to detect problems, Bareiss said.

Novel idea, no doubt. But there was plenty of competition. The concourse at the Wells Fargo Center - rather than being flooded with sports fans - on Saturday was filled almost to overflowing with some of the nation's most talented young software designers. The PennApps Hackathon, which began in 2009 with a handful of University of Pennsylvania engineering students, has ballooned to 2,000 participants from all across the United States and abroad. Student group PennApps organizes the event.

While to many computer hacking has a negative connotation - summoning images of stolen credit-card information and other forms of illegal computer entry - in the computer-science world, it simply means using code to solve problems.

Organizers said the conference, which pays the domestic travel costs of those accepted, is not only the first collegiate hackathon, but also the nation's largest. It has since spawned a host of imitators and a growing subculture of young computer scientists who hop among conferences to compare notes, test their skills, and seek out like-minded people.

The nation's top technology companies have taken notice. The Hackathon's main sponsor is Comcast NBCUniversal, but other tech giants with a major presence included Google, Facebook, Uber, Apple, and Pebble, the Silicon Valley interactive watchmaker. They come to promote their technology and their brands, but also to recruit young talent.

One of those companies was digital survey firm Qualtrics, which set up in a box overlooking the arena where representatives handed out sweatshirts and invited young coders to fill out survey forms for use by recruiters. The Provo, Utah-based firm said it plans to hire hundreds of computer engineers in the coming year.

Comcast, which owns the Wells Fargo Center, handled much of the logistics, from supplying WiFi and Bluetooth access to security. Judging was to take place on Sunday.

The overall feel was something short of corporate, and that was the point. The 2,000 coders who showed up slept at the center, sprawled on air mattresses or simply dozed off in their seats.

"There is something inspiring about being around people who have been up all night coding," said Chris Sharkey, a toxicology student at Pennsylvania State University, who spent the day coding with Kenneth Au and Bill Powell, also Penn State students.

To be sure, part of the appeal of the PennApps hackathon and others like it is the camaraderie. But it also fits in nicely with current theories about experiential learning: that students sometimes learn more by doing.

PennApps director Pranav Vishnu Ramabhadran, a junior focusing on management and technology at Penn, said hackathons give young computer scientists opportunities to actually make things.

"It is a common problem that a lot of engineers have; you learn a lot of theory before you build anything real, so a weekend where we put our skills to the task, that appeals to a lot of engineers," he said.

"You don't really learn these things until you actually [use them]. That creates a real sense of validation."

The PennApps conference, held twice a year, started to gain cruising speed in 2013, when it grew from its original core to about 1,000 participants. That was also the year the conference began to reimburse for travel expenses.

Students from area high schools, colleges, and universities are automatically admitted. Other applicants are admitted on a competitive basis; of those, only 26 percent are accepted, PennApps said.

"It is one of the best organized hackathons in the U.S.," said Grace Zhang, a high school senior from Manhattan who was working on an Android application.

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