For me, stability means uptime and infrequency of application crashes. Unfortunately, OpenBSD didn't meet that requirement on my (standard desktop) machine--it would frequently kernel panic on resume.

On the other hand, I found that OpenBSD has absolutely outstanding reliability and stability on hardware like my ThinkPad X220.

> The bsds are actually less stable than Linux.

> Stable meaning changes, in this context, right? freeBSD changes ABI compatibility with every version.

Every major version, right? From becoming -Stable to ending its support lifecycle, I'd think a FreeBSD version and its ABIs are supported as long as many Linux distro LTS releases.

The major difference being that if you have a statically compiled binary from linux 2.4 it will work on linux 5.5

The only difference will be any shared libraries and potentially the libc. But if we're speaking from a pure technical perspective, the libc is not linux.

Binaries from all the way back from FreeBSD 4.0 work on -CURRENT just fine.

And I seem to remember that FreeBSD can support linux binaries, too.

Apples and oranges. FreeBSD is providing the userland too so it’s not like the ABI change is going to break all the things it might in a Linux distro if the kernel broke ABI.

I know that they change (well, reserve the right to change) syscalls with every major version. But that's not a big deal, since only the base system is supposed to be using syscalls directly; everything else goes through libc.

So, are you saying that they break libc ABI?

How about stability of user interface?

More of what I learned using Linux 0.99 applies to present-day OpenBSD than present-day Linux, and I can’t think of any breaking changes specific to the Linux side that weren’t clear regressions (except apt and dpkg. Those rock.)

NetBSD preserves backwards compatibility for its ABI.