Seven years after two fraternity brothers started Blackboard Inc. in a Dupont Circle rowhouse, they watched its stock surge 43 percent in the District company's first day of trading as a public company.

Stock in the online learning company was priced at $14 a share, began trading at $15.80, rose as high as $23.38 and closed at $20.01.

The greeting Blackboard received from investors surprised some Wall Street watchers. The 43 percent gain is small in light of the triple-digit percentage increases that were typical during the dot-com boom years. But it compares favorably with other recent initial public offerings: Four out of six companies that went public this month slipped below their offering price on the first day of trading, said Richard J. Peterson, a market strategist for Thomson Financial in New York.

"This has given some IPO investors reason to rejoice," Peterson said. "If you have a product and a strong market share and expectations of some earnings growth, you're going to stand above the crowd."

The company's co-founders, Matthew S. Pittinsky and Michael L. Chasen, were in Manhattan to receive the glitzy sendoff the Nasdaq market offers its newest listings. The company's logo glowed over Times Square on Nasdaq's electronic display. Pittinsky and Chasen smiled broadly and hugged after ceremoniously signing the Nasdaq registry.

They also are multimillionaires, at least on paper. Pittinsky's shares and options exercisable by Aug. 16 are worth $12.1 million based on yesterday's closing price. Chasen's holdings are worth $12 million, according to documents filed yesterday with the Securities and Exchange Commission.

Company executives and employees emphasized they weren't succumbing to the exuberance of the dot-com era.

"Naturally, our IPO represents a milestone for this company," Chasen, the company's president and chief executive, said at the Nasdaq listing ceremony yesterday. But he added, "I am excited to roll up our sleeves and get back to work on Monday."

Employees at the company's loft-like headquarters on L Street watched the ceremony via webcam and prepared for an early evening reception that was planned to include friends and family, but not champagne.

The dot-com image has been tough to shake. When the American University graduates co-founded the company, Pittinsky was 24 and Chasen was 25. It was the apex of Internet entrepreneurship, when retiring at age 30 seemed a reasonable exit strategy.

Early on, the company, which attracted $105 million in five rounds of venture funding, was rumored to be planning a public offering.

Chasen and Pittinsky regularly played into the gossip, telling reporters that tapping the public markets was an option they would consider when the time was right. But when the Internet stock bubble burst, there was speculation the more likely outcome would be sale of the company.

With the help of deep-pocketed investors, including Microsoft Corp. and Oak Hill Capital Partners of Fort Worth, Blackboard's growth continued through the downturn. The investment arm of a Washington Post Co. subsidiary, Kaplan Inc., is also an investor in Blackboard. Kaplan uses Blackboard software. Blackboard acquired five other firms, lengthening its customer list and broadening the scope of its offerings to universities. Blackboard has more than 2,000 customers and almost 500 employees.

"In many ways, I think Blackboard is the coming of age of a lot of the Internet opportunities," said April L. Young, a managing director at Reston-based Comerica Inc., a bank that provides financial services to venture funds. Young has known Chasen and Pittinsky for several years. "It was built the hard way: They raised some money, sold some software, raised some more money."

The firm's software helps instructors put course material on the Web. The company also sells technology to manage identity card transactions that allow students to make purchases on campus. The company estimates its software was used by about 12 million students, faculty members and others in 2003.

Now that it has public shareholders watching its quarterly performance, Blackboard's challenges will include expanding further into new markets, such as international universities, K-12 schools and corporations. The company and its competitors already have their learning software on 90 percent of U.S. college and university campuses, industry analysts say.

Investors interested in the stock are likely looking at the company as part of the education sector rather than as a technology or Internet industry, said David Menlow, president of IPO Financial Network Corp., a Millburn, N.J., firm that analyzes public offerings. And while the company has not yet been profitable for a full year, it is expected to report a profit in 2004, he added.

Blackboard lost $1.4 million in 2003, compared with $41.7 million the previous year. Its revenue rose to $92.5 million from $69.9 million.

For many in the tightknit Washington technology community, Blackboard's successful IPO is cause for celebration. The company is one of the few non-government-contracting companies to go public since early 2000.

"The fact that one of our local ones, in this pretty tough environment, is getting out, is good," said Arthur J. Marks, general partner at McLean-based Valhalla Partners, a venture capital firm. And because this company's executives waited long enough to become seasoned and polish their business model, they may serve as important role models for other entrepreneurs, Marks added.

"It's a milestone for the company and a milestone for the community, especially the District," said Raul J. Fernandez, chief executive of Reston-based ObjectVideo and founder of Proxicom Inc.

Blackboard founders Michael L. Chasen, left, and Matthew S. Pittinsky held off going public until after the Internet stock bubble burst. They are worth about $12 million each now.