[mof:]
I found the following issue on tcl 8.5:

One if my windows machines is named "Mof13.somedomain"
[info hostname] returns "mof13.somedomain" (everything lowercase)

As some applications I use with tcl are case sensitive to the hostname and I didn't that this machine had a capital "M", I searched for a bug in my tcl script for 4 hours...

Windows' hostname on cmd.exe returns the correct "MoF13.somedomain", I expect [info hostname] to do the same.
Therfore I think [info hostname] is not reliable.

A workaround for this ambiguity is to use [exec hostname] on windows, but i guess it's not platform independent...