You must not write kernel extensions for a living if you think a closed Mac OS X kernel is tolerable. Apple's kernel documentation is the most neglected of all their developer documentation. Ever seen Apple's reference for the core kernel API? Nope, because it doesn't exist...
Aside from that, the potential loss here for Mac users is incalcuable. Look at the Linux kernel, and the thriving development community around it. Interesting new features get added, considered, beat into shape. Performance gets tuned. Bugs get squashed quickly. Entire subsystems get replaced with better ones (sometimes).
Look at Safari. It's thriving as a fully accesible open-source project, where the app itself isn't actually opensource, but the foundation library which implements most of the functionality _is_. It's true that the pool of WebKit developers to draw from is wider, and the barrier to entry lower, but it's also a function of the stark difference in attitude of the development teams -- Safari's leadership "gets it." xnu's hasn't and doesn't (and now probably can't, since it's likely locked down from the top).
Apple has thrown away a golden opportunity to open the kernel up and make kernel development more accesible to developers outside of Apple. There is a huge set of developers who would be happy to contribute, but Apple never really committed to making the kernel accessible as open source. The first thing Apple should have done six years ago was to make the kernel compile with just the normal devtools installed. But they just threw it out there unmodified. Apple employees working in their spare time eventually fixed this, years later and eons too late.
by Chris — May 17
Aside from that, the potential loss here for Mac users is incalcuable. Look at the Linux kernel, and the thriving development community around it. Interesting new features get added, considered, beat into shape. Performance gets tuned. Bugs get squashed quickly. Entire subsystems get replaced with better ones (sometimes).
Look at Safari. It's thriving as a fully accesible open-source project, where the app itself isn't actually opensource, but the foundation library which implements most of the functionality _is_. It's true that the pool of WebKit developers to draw from is wider, and the barrier to entry lower, but it's also a function of the stark difference in attitude of the development teams -- Safari's leadership "gets it." xnu's hasn't and doesn't (and now probably can't, since it's likely locked down from the top).
Apple has thrown away a golden opportunity to open the kernel up and make kernel development more accesible to developers outside of Apple. There is a huge set of developers who would be happy to contribute, but Apple never really committed to making the kernel accessible as open source. The first thing Apple should have done six years ago was to make the kernel compile with just the normal devtools installed. But they just threw it out there unmodified. Apple employees working in their spare time eventually fixed this, years later and eons too late.