Call it the ultimate double play: Open source coupled with software as a service (SaaS). Using that formula, SugarCRM is striving to double its size this year, asserts CEO John Roberts.

During a phone interview earlier today, Roberts declared the age of proprietary, closed software to be nearing its end. He asserted that even traditional SaaS deployments from companies like Salesforce.com will face intense pressure from open-source SaaS alternatives.

A prime example: SugarCRM has lined up more than 125 integration partners; roughly 20 of those partners now host SugarCRM and offer it as an on-demand service to their customers. SugarCRM itself hosts its software in Silicon Valley, and plans to introduce a hosted offering at a European data center soon, Roberts added.

Still, Roberts welcomes head-on SaaS competition from SugarCRM's own partners -- because customers are demanding "infinite knowledge" and want to evaluate every aspect of a SaaS service before choosing a partner, he added. And plenty of companies continue to deploy SugarCRM on-site. But SaaS coupled with open source, it seems, is the story everyone wants to talk about -- from Silicon Valley to Wall Street.

So, what is SugarCRM's biggest challenge? Apparently, it's finding talent. "We're at over 150 employees now and growing like crazy," declared Roberts. "All I hear about is recession talk, but we're growing like mad and working hard to keep up with demand and stay focused. I suspect we'll double in size this year."

Longer term, Roberts hopes SugarCRM manages to launch an initial public offering within a year or two. In the meantime, the company just secured another round of funding.