Kristine Harper was a high school senior when she took her first mainframe class. Six years later she's a professional mainframe programmer and platform evangelist to young people beginning their IT careers.

"I always say that it's not my fault I got into this business. It's in my blood," says Harper, whose parents are mainframe software developers.

At 23, Harper is among the new generation of mainframe professionals gearing up to take the place of retiring veterans. This new generation is sparse: Industry watchers say there aren't enough new recruits to replenish the ranks. When research firm Gartner surveyed 100 mainframe users late last year, 25% of respondents said their company already is affected by a mainframe skill shortage, and 40% said they expect to be affected in the next couple of years.

One reason for the skill shortage is a lack of exposure to mainframe computing in college, Harper says.

Her interest in mainframes began with an independent study she did with her father during her senior year of high school. "He taught me all the basics about mainframes, a little bit of [Job Control Language] and Assembler, and machine code and all that good stuff," she says.

The formal education all but ended there, however. With the exception of a single Assembler class at the University of Arizona in Tucson, Harper learned everything she knows from summer internships at Neon Enterprise Software (where today she works full-time as an associate programmer), conferences put on by Share, a nonprofit IBM user group, and her father. "I definitely did not pick up what I know from school," she says.

Alan Antonuk didn't get his mainframe training in a university classroom either. "The school I go to doesn't offer any mainframe-specific classes," says Antonuk, who in the fall will begin his fifth year as a dual major at Michigan State University in East Lansing. Antonuk, 22, is due to graduate next May with degrees in computer science and physics.