Nationally, the Washington area ranks eighth when it comes to venture capital dollars invested, ahead of hubs like Seattle and Denver, according to the National Venture Capital Association. Narrowing it down to venture capital investing in information technology, the area ranks sixth, just behind Boston and the New York metro area.

“There is this whole new generation of companies that aren’t just playing to the typical D.C. niches of government and health care,” said Tige Savage, who started Revolution, an investment firm based in Washington, along with Donn Davis and Steve Case, co-founder of AOL. “They might come to D.C. to work for the government or a contractor, but are often eager to start their own companies,” he said.

Many credit the Obama presidency for making Washington “cool” again for the under-30 set. But what else is putting the capital city on the start-up map?

For one thing, there is a wellspring of technical expertise  all those engineers and developers who come to Washington to test missiles and write GPS software for the military.

“Staffing is one the biggest challenges for any company, and being in D.C. has given us an edge in terms of attracting the top people,” said Tim O’Shaughnessy, co-founder of LivingSocial. “Being a big fish in a small pond, we’ve become the destination for people in this area looking to work at a consumer Web site.”

There is also the visibility that comes with being a city that has not yet become known as a tech hot spot. In October, Ryan Healy, 26, relocated his start-up, Brazen Careerist, a career social networking site for people in their 20s, from Madison, Wis., to McLean, Va. Mr. Healy said the company had won attention from investors and media outlets just for moving to the area. “That wouldn’t happen in other cities,” he said.

Ed Barrientos, 45, chief executive of Brazen Careerist, has invested $4.5 million in seven companies based in the Washington area since the mid-1990s. He chose the area over others because the competition for investors was not as stiff. “The value of investing in a place like D.C. is that you can find a company doing extremely cool stuff, but still get a fair valuation,” he said.