[kens]

I'll mention that mainframes also had extensive libraries of shared software. The IBM user group SHARE (Society to Help Avoid Redundant Effort) started in 1955 to share software and had hundreds of programs in an IBM-maintained library. IBM also had the Contributed Program Library. Software ranged from math libraries to programming languages to statistics packages to nuclear reactor simulators.

References: https://www.si.edu/object/archives/sova-nmah-ac-0498 http://www.bitsavers.org/pdf/ibm/650/programLibrary/Addition... https://en.wikipedia.org/wiki/IBM_Type-III_Library https://web.archive.org/web/20110322030511/http://www.bitsav...