"I do believe that as developers, we cannot fail to consider the importance of this. The economic drivers are simply too profound. This really is going to change our lives," said Rod Johnson, who is VMware's senior vice president of cloud application platform, during a presentation at the ZendCon 2010 PHP conference in Santa Clara.

Acknowledging some audience hesitance about cloud computing, Johnson displayed onscreen an InfoWorld news article about a tepid reaction to cloud computing at the event, which ran on Tuesday. "I think despite the skepticism, the shift to cloud computing is going to happen."

Johnson also stressed the need to access diverse data sources and running applications in public infrastructure. "So if you think about it, it makes no sense for small or medium-size enterprises to operate their own data centers," Johnson argued. "I think it's not merely an issue of cost. I think it is also an issue of environmental sanity."

Cloud computing is akin to the evolution of electricity, in which users use a utility rather than run their own generators, said Johnson, who is best known as the founder of the Spring Framework for Java development.  

After Johnson's presentation, an audience member acknowledged cloud computing as a trend. "I think that's the way things are going. Most everything's online," said Darcy Pleckham, Internet technologist and architect at Clearinghouse, a financial firm.  

VMware's efforts for cloud application developers include Code2Cloud, featuring cloud development and collaboration tools. Although initially geared to Java, developers may see versions for other platforms, such as PHP and Ruby on Rails, Johnson said.  

Johnson also noted acceptance of open source in the enterprise. "A few years ago, open source was subversive." Now, it is accepted, he said. "Open source in many respects has helped customers avoid lock-in more successfully than standards bodies have done