I was recently referred to a skills testing site, proveit.com. They have a number of Linux skills tests available - all of which can only be taken in Internet Explorer running on Windows.
It occurs to me that yes, there is a world where all the admins run Windows and manage their Linux systems and servers with putty, or more likely vnc or a web interface. I'm sure this is more common in the "enterprise" Linux world than in my experience.
Besides the tests working only in Windows, they say that they were tested in Firefox 2.0 and IE6 - the latter being a notorious security hole that Microsoft has struggled in vain to get rid of.
Anyway, just so you know, anybody citing proveit.com testing as evidence of Linux knowledge is pulling your leg.