[toast0]

Based on how often they pull in updated bits from FreeBSD (pretty much never), an Apple fork of Linux would be more or less Linux 2.4 today.

I don't know what the loss that open source suffers is in this context?

I don't think Apple would need to spend less time or money on their kernel grafted ontop of Linux 2.4 vs their kernel grafted on top of FreeBSD 4.4

[WD-42]

Because presumably the GPL would force them to release their modifications. Apple gets/got away with leeching off the BSDs because of the permissive license.

[toast0]

They release their kernel source more or less timely without the GPL.

[zigzag312]

A bit off topic, but is there any data or estimates of how often big companies use modified versions GPL software/libraries for their web services without releasing their modifications?