Not all companies that suddenly go open-source get criticized. Terracotta Inc., a San Francisco maker of Java clustering software, has gotten nothing but kudos since switching to open-source in December, according to CEO Amit Pandey.

"We are a new company and our product only came out six months before that," he said. "If we'd waited say a year or a year and a half, we'd probably have run into more resistance."

Blurring the boundaries

The sudden drive for ideological purity is partly due to the confusing period in open-source's evolution we seem to be in. The prevailing business model is the almost-oxymoronic 'commercial open-source.' The biggest open-source announcements last year were all by companies traditionally hostile to open-source.

Take Microsoft, which now the large percentage of users who run popular open-source applications such as SugarCRM, Jboss and MySQL on top of Windows. The Redmond company also inked that controversial deal with open-source standardbearer Novell Inc.