The Librarian

The Librarian is a version control system and source code management software product originally developed by Applied Data Research for IBM mainframe computers. It was designed to supplant physical punched card decks as a way of maintaining programs, but kept a card model in terms of its interface. During the 1970s and 1980s it was in use at thousands of IBM mainframe installations and was one of the best-selling software products in the computer industry. After Applied Data Research was acquired by Computer Associates in 1988, the product became known as CA-Librarian. After that company was acquired by Broadcom in 2018, the product became known simply as Librarian. History Most computer source programs in the 1960s were kept on punched cards, which was problematic due to the amount of physical space they took, the constant chance of card decks being dropped or otherwise damaged, and problems with keeping a history of changes to the program. Even into the mid-to-late 1970s, when other forms of computer input emerged, the punched card deck was still the most important of these, and this was also true for the source code for computer programs themselves. During its early years, Applied Data Research (ADR) was developing Autoflow, a program for automatic flowcharting, which is often cited as one of the first commercial software applications. The ADR staff wanted something to help manage the increasing size of the Autoflow source code base. Martin Goetz, an ADR co-founder, had used the UNITYPER system during a prior employment with Sperry Rand. This device wrote typed input onto a metal magnetic tape. Goetz realized that source code did not have to live on punched cards, but instead could be kept in stable magnetic storage; a program called the Librarian that did this was then built for in-house use.