Yoni Rabkin wrote:

> As an additional selling point I'll add that this would bring at least
> those two to look and behave like conventional Emacs pop-up windows(*).
>

I'm still not seeing any real connection to sync vs. async though, 
beyond it being unworkable to _naively_ leave buffer-read-only set on a 
buffer that's being async filled with process output?  That's not a 
great reason to leap to sync, though.

Assuming that anything in net-utils.el that's just run via 
net-utils-run-program rather than using a comint-derived mode like 
ftp-mode is effectively a simple one-shot output-only
command where your desired  treatment is appropriate, you could do 
something like the attached ?

i.r. Means you get a read-only popup output dismissable with "q", even
when the command is dawdling mid-output ?

I'm not sure you wouldn't want separate major mode and font locking
for the separate kinds of even simple network utility.  Of course,
the outputs of such utilities can vary platform to platform,
so going much beyond highlighting IP addresses and hostnames
might be on thin ice.