According to this report, Tcl/Tk and Expect are used at the US DOD:
http://www.egovos.org/pdf/dodfoss.pdf
although they don't go into the specifics.
Tcl 8.3 is blessed by DII COE [L1 ] as a COE Product. This effectively means, that if you need to be DII COE compliant, you can use Tcl. Perl is the only other scripting language listed.