Last I checked, Cisco Systems' CWSI network management platform was comprised of a bazillion smallish perl ^{(and java)} programs.   Never got to talk with any developers, but expect that was done at least in part to ease multiplatform support - Win32, Solaris, AIX, etc.

CiscoWorks mostly isn't a desktop program, but is clearly a commercially viable application family, costing several ^(many?) thousand $USD.
    cheers,
    Don
    striving toward Perl Adept
    (it's pronounced "why-bick")