Tom Clement has reinvented his career before. In 1984, he realized that working in technology would suit him better than his job as a litigator in Texas. "I came home one day from work, and I was used to being really tense," he says. "But that day, my secretary's recorder had broken. I'd taken it apart, put it back together and somehow, it worked. I was whistling and in a good mood because of it, and my girlfriend heard me and said, 'Tom, maybe you were made for a different line of work.'"

After moving to California and taking a night class at the University of California, Berkeley, in C-programming, he put his law ambitions aside and took a job at a C-compiler company, taking pieces of code and translating it into a language that could work on Motorola hardware.

Today, Clement, a senior developer at Serena Software, might be facing a bigger career test: software as a service (SaaS), the movement of software to the Web. SaaS, one flavor of today's hot buzzword, cloud computing, refers to applications that users access over the Web and which live on physical servers hosted by the software vendors or a third party, not servers owned and cared for by an in-house IT department.

Today, most large companies use a mix of both traditional apps that they run on premise and some that are hosted offsite, such as Salesforce.com's sales and CRM-related apps. Enterprise adoption of SaaS applications has been aggressive. According to a CIO.com survey on cloud computing, 84 percent of respondents are currently running SaaS-type applications. Meanwhile, a survey published earlier this year by Kelton research found that 73 percent of large companies have already or plan to adopt SaaS technology in the next 18 months.

A shift away from on-premise apps has implications for how companies staff their IT departments in the future, according to CIOs and IT industry executives. Change is afoot for developers as well as the thousands of IT support and maintenance professionals taking care of traditional software at companies of all sizes, in all industries.

Case in point: Tim Davis, CIO of Popeyes Louisiana Kitchen, a national fast food chain based in Atlanta, only has six IT people on staff and not one production server on premise. With no production servers or apps to run, says Davis, "Three [people] are dedicated to making sure the restaurants have whatever technology they need. The rest are project managers and manage our relationships with vendors."