Imagine you are one of the original employees at a very small software company. After some initial rocky years, the company achieves an enviable level of success, its flagship product becoming a fixture on countless trading desks. You, too, are successful. No longer an employee, you are the company's CEO. Then, you realize every small software company's dream: you and the firm's other principals are bought out by wealthy investors.

So, now what? Scuba diving? Mountain climbing? Zen Budhism?

Philip Brittan, former CEO of the wildly successful Astrogamma, best known for the popular option pricing module FENICS, had other ideas. In 1995, while Astrogamma was being purchased by a group of venture capitalists who changed its name change to Inventure, Brittan and Astrogramma's former vice president of development, Frank Rose, started a new company called Sphere Software Engineering.

"Maybe, in retrospect, I should have taken an extended vacation," says Brittan, "but Frank and I were very excited about our new firm, and we wanted to get going immediately. I think my years at Astrogamma really whetted my appetite for entrepreneurship."

Offering financial engineering and custom software development services to banks, brokerages and corporations, Sphere has built up a considerable client base through word of mouth during the past year. But unlike Astrogamma, which succeeded as a specialist in a very narrow market niche, Sphere offers a more general menu of services, applying Brittan's and Rose's intensive knowledge of the software development process to a wide variety of projects and technologies.

Already, Sphere has built a wide selection of custom modules in the financial arena. For example, at one large European commercial bank, Sphere designed a class library structure that makes it very easy for the bank to add new types of derivative instruments to its pricing and risk management systems. For a leading financial data vendor, Brittan and his colleagues are developing a suite of intranet-based analysis and risk-management tools, which will be delivered to wide community of users through a performance enhanced Web browser.

"The opportunity to work on a broader selection of projects and to implement cutting edge technologies is very appealing," says Brittan. Indeed, for him, software development and design is a labor of love. Growing up on a ranch in Montana, Brittan traveled east to obtain a degree in computer science from Harvard University. However, even before he received his diploma in 1988, Brittan began working as a freelance consultant on trading desks in Switzerland during summer vacations. It was at this time that he met Peter Cyrus, the founder of Astrogamma. Upon graduation. he went to work as Astrogamma's very first programmer. After seven years with Astrogamma, Brittan became the president and CEO in 1993, and he left to form Sphere in 1995.

In his spare time-which is quite limited these days-Brittan composes music and shares the results with family and friends. "Musical composition is a creative process, and I enjoy it very much," he says. "I also get the same kind of enjoyment 'composing' an elegant software application or systems design."

Earlier in his professional life, Al Scarpa spent most of his time selling software to corporate IT departments. Scarpa finds his new life as general manager of Infinity Technology's North American operations quite a bit different-and a lot more satisfying. "In my other jobs, I was marketing software aimed more at helping clients improve their access to information needed for division support," he explains. "I like the fact that I'm helping to provide software that will actually help clients make more money."

Scarpa quickly discovered that in the derivatives world, the business people lead software development-not the other way around. "In the derivatives market, you have a lot more contact with the business people," he says. "That makes sense when you realize how important good systems are to their bottom line."

Scarpa worked in sales positions at a number of different software companies, including ASK Computing, a corporate application-development firm. In 1993, ASK was acquired by Computer Associates, a provider of enterprise-wide mainframe and client/server-based manufacturing software. After the acquisition, Scarpa headed up sales for Computer Associates' Northeast region.

Scarpa was born in Paris and spent most of his childhood summers there, logging many miles over the ''Pond'' just before the frequent-flyer-mile era began. He got a bachelor's degree in economics and computer science, and later an MBA in international business and marketing, from New York University. During the summer months Scarpa spends much of his free time in a little corner of the Pond, navigating his Sonar sailboat through Long Island Sound. A member of the Larchmont Yacht Club, Scarpa is a competitive racer.