How can something given away for free end up being the world's largest industry of its type?
According to John Powell, CEO of open source content management vendor Alfresco the value of open source is not what it generates, but what it saves, and that's worth billions.
"Open source is now the world's largest software industry," Powell declared during his keynote address as the first Alfresco community conference in Sydney, Australia.
"You measure it in the savings people are making in licence fees," he said. "Licence fees don't add any value to the product and are purely a transfer of wealth from consumers to software vendors."
By that rationale, the open source software industry is worth $60 billion (£30 billion) - not from sales but from what customers have saved by choosing an open source product over a proprietary one with hefty licence fees attached.
"Open source itself is powered by people and it is allowing software to be deployed in a way that hasn't been possible before, and what that is doing is commoditising the industry," Powell said. "If the database industry is worth $10 billion, the open source database industry might be worth $1 billion and the nine billion left over stays with the customer to help make the product work."
Powell boldly remarked that open source is not just software, it's "the most profound change in the computer industry since its inception".
"In the last couple of years it has moved from being the province of geeky individuals to becoming mainstream," he said. "Sun bought MySQL, Yahoo bought Zimbra, and Citrix bought XenSource for $500 million - a company with less than $1 million in revenues showing open source is about more than the traditional revenues of proprietary software companies."
Powell also talked up the success of the Alfresco open source content management system, saying the product has been downloaded over a million times and is running on some 30,000 production servers.
"We now have over 500 enterprise customers and to acquire this customer base in the traditional way would have been virtually impossible," he said.