I had a similar job to this when I was a grad. I got given an IDE that was written in korn shell to maintain. Not as mission critical as this sounds, but was t

I had a similar job to this when I was a grad. I got given an IDE that was written in korn shell to maintain. Not as mission critical as this sounds, but was the only way to edit, compile, link and deploy around 6000 COBOL programs that made up a very large and expensive financial services platform. It also integrated with the SCM (unix RCS!), did checkout, checkin, merging, branching and all manner of amazing things. There was probably 30 devs who used it, all running on a HPUX server. It was very powerful, but a total nightmare to look after.