We've had iBCS for x86 Unix "emulation" for even longer. You don't
need chrooted environments, and shouldn't. The iBCS philosophy is
that "foreign" programs should just work. Not lose chunks of
file space just because they are forced into an unexpected chroot.
The solution which NetBSD uses for doing emulation (and which I think is
a good idea), is that when you are running a (for example) Linux binary
under emulation, file lookups first check to see if the file is in the
linux directory tree. If the file exists in there, that file is used;
otherwise, the file lookup uses the normal file.
This allows NetBSD to put the Linux-specific libraries in
/linux/usr/lib/... without needing to worry about naming conflicts
between Linux libraries and NetBSD libraries.
I could imagine something similar for iBCS, so that "foreign" programs
can work, but all of the SCO-specific libraries end up in an
SCO-specific tree. (And all of the i386 Solaris libraries can end up in
a different tree, without worrying about the inevitable namespace
clashes).
- Ted