[dijit]

I'm a bit naive, but I don't think that's necessarily a requirement.

It might be commonly held convention, and thus, an assumption, in Linux (and, broadly, UNIX) but I don't think it's true inside VAX or even Windows, so I don't think it's a requirement.

Unless I've missed something (which is totally possible, this is not an area of OS design I've spent much time).

[lanstin]

But also UID, groups, controlling TTY, process group, capabilities, pipes, shared memory, etc. and the file descriptors while maybe not inherently needed are how a lot of Unix plumbing works.

[sjmulder]

Even DOS has environment inheritance!