Name of company: Aecometric Corp. 
Name of woman leader: Jill Anderson
Based in: Richmond Hill, Ontario, Canada
Description: Designs and manufactures custom, large-scale industrial combustion equipment for the global market
Began: 1978
2003 sales: $1.5 million
2007 sales: $23 million

What was the inspiration for your business?
Aecometric was her husband's venture, but when he suffered a stroke in 1996, Jill Anderson was faced with the decision to sell or carry on. She decided to keep the business going. "It was a bit of a crusade," she says, "but I assumed I was just going to hold the fort for a couple of years. Unfortunately that didn't happen; but so far, so good."

How much did it cost to start Aecometric?
Anderson's husband started the business in their spare bedroom, and it took a couple of years before he moved into an office and hired employees. At the time, the couple had a new baby, and they kept things simple. "It was probably a few thousand dollars," she says.

You've obviously come a long way from humble beginnings. What do you think is the key to growing a multimillion-dollar business?
According to Anderson, persistence is key. She points out that after 9/11, the entire industry was in bad shape. "A lot of companies were going under . . . but I was determined to be the last man standing," she says. "I remortgaged the farm and everything, but you have to decide whether you want to take those kinds of risks."

How do you balance your family and business responsibilities?
When she first took over Aecometric, Anderson had to care for her husband and children. "It was very draining," she remembers. She adds that she has two sons and a daughter, and her daughter now works as the company's operations manager.

Do you have any examples about juggling family and business life?
When her youngest son was still in school, Anderson would pick him up and bring him to the office if she had to work late. "He had his own desk, and I'd be right there for him while he did his homework," she says.

What other advice do you have for entrepreneurs who want to grow their business?
When her husband's health failed, most of Aecometric's employees left, assuming Anderson wouldn't keep the business alive. "It was a matter of sheer determination," she says. "At that level of business, nobody accepts any excuses, so I think it's a matter of getting at least a couple of good people that you can rely on: one in finance and another who can act like your backup."

How do you relax?
Anderson paints. "That was my background, fine arts--a little different from what I do now," she laughs. "Or I cook, which is a good thing because nobody's going to do it for me."

What books are you reading?
Anderson loves to read, and goes through about five books a week. She reads business-related titles, but enjoys fiction as well. Recently, she finished Cormac McCarthy's The Road.

Do you have any final words for business owners?
"Just hang in there," she says. "I think a lot of people, especially in small business and entrepreneurial [ventures], give up too easily. You get to the hard part, and sometimes you just have to chew through it."

Click here to see the Top 50 list.