Free software's awfully like sausages - wonderfully tasty, but sometimes you suddenly discover that you've been eating sheep nostrils for the past 15 years of your life. The typical direction is realising that you've build your entire business model on something that you're actually legally obliged to give to your customers and now they're actually trying to assert their rights, but sometimes people make assumptions about freedom that don't hold. Apple last released a free version of their kernel source in 2006. Everything since then has been encumbered by additional use restrictions.
Still, much better than Microsoft - huge portions of the OS source code are available for anyone to download, examine, modify and rebuild. Apple's to be commended for dropping so much code to the community despite it having bought them almost nothing in return. But if anyone from Apple's reading, I'd love to fix up the thermal handling on your hardware under Linux. I suspect we're doing something horrible to your machines, but I don't really know what yet.
