I wonder if Wodehouse ties together both types of heroes in Bertie and Jeeves! Though it's been decades since I read a Wodehouse book, I'm just uncontrollably laughing now just thinking about it! My grandfather had pretty much the whole collection.
I'm pretty sure it was for a product (server side), not an internal dev tool. Back in 2000 one of my roommates was an intern with the VS team and he said a lot of the devs were using emacs.
Well how the tables have turned! Only about 3 yrs back I was having a conversation with a Microsoft engineer about them evaluating a closed source Hadoop clone because Microsoft policy prohibited them from using open source.