Laurie F. Wurster, research director at Gartner Research, explained that Gartner has undergone a major change in methodology.
"Previous to this year we counted new license revenue," Wurster told internetnews.com. "This year we're doing total software revenue, which includes license revenue. It also includes updates/upgrades. It includes subscriptions and ASP models. We also include support revenue and maintenance contracts.
"We feel this is a better long-term predictor of the market especially as markets start to mature," Wurster added.
Wurster is the co-author, along with Fabrizio Biscotti, of the report "Market Share: Application Development and Project and Portfolio Management, Worldwide, 2005."
Open source is significantly impacting three areas of application development, according to Gartner, which includes testing tools, change configuration management and Java development.
"In our previous method using license revenue only, there was really no way to count what the impact of open source was except to say that the application development market is declining," Wurster explained.