This brings back memories of an ancient program called "patchy" that I encountered during my PhD. Fun story, I was one of the last students doing his PhD at th

This brings back memories of an ancient program called "patchy" that I encountered during my PhD. Fun story, I was one of the last students doing his PhD at the Tevatron, a large particle accelerator near Chicago, before everybody's attention moved to the LHC. Our collaboration was winding down, and close to the end of my thesis I realized that there was nobody producing the simulations that I needed anymore, so I had do it all myself. The first step was building the software. One program I used has been maintained by the same guy since the 70s, and you could see the accretion of layer upon layer as new scientific models got added to the program, but it was never rewritten. The code itself was in glorious FORTRAN 77, and to compile it you needed the aforementioned patchy. A patchy file is a plain text archive of all your source files much like in OPs stamp. In addition, you can add directives to each file to do a primitive form of conditional compilation (e.g. to include certain models, or to run on AIX). I really wanted to use this one program because it could simulate things no other program could do. But the biggest hurdle was actually compiling patchy, which required a specific version of CentOS, CERNLIB, two decades worth of patches on top, and a crazy bootstrapping procedure. I especially recall a manual for patchy, which proudly talked about laying a software foundation for the soon to be built "superconducting super collider" in Texas (which was cancelled while I was still in elementary school). The episode made me realize how deep the stacks are sometimes behind the legacy software that we use.