BSD's don't tend to have distros. So for example OpenBSD has a ports tree maintained by the ports team for OpenBSD. The operating system is free to break ABI's

BSD's don't tend to have distros. So for example OpenBSD has a ports tree maintained by the ports team for OpenBSD. The operating system is free to break ABI's from release to release as the ports tree is audited, fixed, and recompiled for the new release. The Linux kernel can't freely do this as then the ABI break is placed on various distro maintainers and software authors because there is no clear point in time they can say ABI $FOO will break on date $BAR.