Mark IV appears to have been a report generation system, what was known in the 60s and 70s as a “file management system” (readers more familiar with older micro-computer software than mainframe software should compare this to “card management” tools like HyperCard or Windows’ Cardfile, and larger-scale software like Crystal Reports). GIRLS, the first iteration of the software, was described in the December 1962 issue of Datamation, but that doesn’t seem to be archived.
Mark IV is historically significant because it is part of a line of software with a number of “firsts”; Luanne Johnson’s paper, A View From the 1960s: How the Software Industry Began, provides more context. Mark IV is one of the first software packages, if not the first, to be sold as a separate commercial product. It is also the first piece of software to have its development sponsored by multiple potential clients. The series of software leading to Mark IV, developed by John Postley, was acquired by Informatics when Hughes “sold” AIS (Hughes actually paid Informatics to take over AIS); Postley wanted to port Mark III to the new IBM System/360, but Informatics couldn’t afford to fund its development in full, so Postley lined up five customers who each ponied up $100,000 to fund the project. Since Mark IV was the first software package sold as such, all the practices around such activities had to be invented, starting with setting a per-customer price ($30,000 initially, after much discussion). Informatics initially provided upgrades and support for free, but faced with mounting costs, started charging for support four years later. To avoid allowing customers to copy Mark IV, Informatics also invented the “licensing agreement” model for software distribution — customers didn’t buy the software outright, they bought a license to use it.
Postley mentions that Mark IV may also be the origin of the first software patent application; this was unsuccessful in the US, but patents were granted in Australia, the UK, Canada, and Japan. I haven’t looked the patents up, but they should provide much more insight into what the software actually did.
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