[ploek]

The BSDs have diverged significantly since then and not just in userland. Unlike Linux distros they do not all have the same kernel. There are of course common parts in their kernels, many of which date back to Unix, but there are also big differences between all of them.

I was also surprised to see Sailfish OS, Meego and Maemo listed separate from Linux, but my guess would be that the list comes from the build system of curl. Everything that is its own build target is listed there.