William Roetzheim is not a delusions-of-grandeur kind of guy. He sets an achievable goal, achieves it, then moves on to the next thing. So, a year after making the Inc. 500 with his software company, Marotz, he sold the business and launched Cost Xpert Group around a cost-estimating tool he had developed at Marotz. He built that business to a few million dollars and then, yes, sold it. "I always plan to sell when I get to $5 million," says Roetzheim. "I like starting companies. I don't want to run something big."

Retired at 50, in 2005, Roetzheim made a list of all the things he hadn't done "because they didn't pass the litmus tests of, Will this help me in my business pursuits?" First off: writing poetry. But he didn't want to waste time wandering lonely as a cloud. "I treated poetry the same way I treat everything," says Roetzheim. "There's a mission, there's a goal, and there's an objective. I even had Microsoft project plans for it."

For a year, Roetzheim spent six hours a day reading books of and on poetry. He eventually self-published a volume of verse and compiled an anthology, The Giant Book of Poetry, which is taught in colleges across the country. That anthology underwrites the small press Roetzheim founded to publish his work and the work of a dozen other writers. He also began writing plays about famous poets; four of the works have been staged in New York City. He paints and has had a gallery show.

In 2008, Roetzheim bought and restored the Victorian house next to his own in Jamul, California. He helps his wife run it as an arts colony-cum-bed and breakfast. Guests go there to paint and work on scripts. Playwrights come by for readings, and patrons are introduced to artists at monthly dinner parties.

"I hate to spoil the illusion, but I'm not doing much of the arts stuff anymore," says Roetzheim. "I had met all my goals and objectives there. So now I've started another company." Level 4 Ventures offers project-management help to companies such as IBM and Accenture. Roetzheim plans to expand the company to a few million, then sell.