During his keynote address today at the Linuxworld Conference and Expo in Sydney, Maddog said the biggest challenge to open source is "people not thinking."

"People are accepting what companies say about software and not questioning it," he said. "Business is about managing risk and if people don't let you control the software, you have given up control of your business."

Maddog was almost seminal in his appraisal of free and open source software (FOSS), saying although a lot of people think free software is gratis, there's "no such thing as a free lunch."

"Free software is the freedom to use software for whatever purpose [and] the only freedom we don't allow is the freedom to limit another person's freedom," he said. "[Vendors] are afraid customers will go elsewhere if they're not locked in. But this is slavery."

Maddog reminisced about times pre-1980 when most software was created as a service and there was no "shrink wrap" market.