A program that I've been using for the last 20 years, didn't work on one of my new servers. On investigation, it didn't work on another one either. The problem was that these are both 64 bit servers, and I've installed 64 bit linux on them. The program was expecting to run on a 32 bit machine.
So I googled. Unsurprisingly, no-one today has heard of the program, it's very obsolete. Except that it still does what I need.
Fortunately, I kept the source code. With Linux, you can always download the source code. I put that onto the server and tried to compile it. Oops - no C compiler! So I downloaded the C compiler with "yum install gcc", and tried again. This time, it complained that it couldn't find the jpeg library. So I told it where that was, and then it complained that the jpeg library object code wasn't 64 bit. So I deleted all the object code and recompiled the jpeg library. That worked. And I tried to compile the program I needed - and that worked!
That's one of the great things about linux. Even a 20 year old program can pretty easily be made to work.