PATCHY is a source code management system that has been in use in High Energy Physics for many years. It is used for the maintenance, distribution and installation of almost all of the routines and packages that make up the CERN Program Library.
PATCHY and the associated auxiliary programs serve in development, maintenance, and inter-computer transport of source programs. Suitably structured source files containing several versions of a given program permit code selection and code modification (down to single-statement-level) by simple control cards to YPATCHY. Compacting and structuring of card files for efficiency (YTOBIN), maintenance of compacted files at the deck level (YEDIT), creation of machine-independent, transportable files (YTOCETA) and listing of compacted files (YLIST) and others are simple auxiliary operations in this environment.
Each of the PATCHY programs is a self-contained executable module.
On Unix machines at CERN, these are typically found in the directory
/cern/pro/bin.