I worked for the web development team at the BBC (Bush House in London) on contract in 1999. The majority of our team used Mandrake Linux (version 6 at the time!) on our desktops. The development language of choice was Perl. The database platform was Oracle but prototyping was done locally using MySQL.
I think it was just easier to run a UNIX environment locally since that was what we were developing for ... - being a non-profit organisation probably allowed for the leniency in desktop policy that made such things possible!
It was a fun place to work!!