A major resource of SHARE from the beginning was the SHARE library. Originally, IBM distributed what software it provided in source form[2][3][4]
and systems programmers commonly made small local additions or modifications and exchanged them with other users. The SHARE library and the process of distributed development it fostered was one of the major origins of open source software.[5]
In 1969, members of SHARE in Europe formed a European Chapter of the organisation, which was formalised in 1966 as the "Share European Association (SEAS)", later SHARE Europe (SEAS).[6] The last meeting of 1994 was jointly held with G.U.I.D.E. At this meeting it was decided to dissolve both SHARE Europe and G.U.I.D.E. and establish the new European IBM users group GSE (Guide Share Europe).
SHARE later incorporated as a non-profit corporation based in Chicago, Illinois and as of 2013[update] is located at 330 N. Wabash Ave. The organization produces a newsletter and conducts two major educational meetings per year.
In September 1999, GUIDE International, the other major IBM mainframe users group, ceased operation. Although SHARE did not formally take over GUIDE in the United States, many of the activities and projects that were undertaken under the aegis of GUIDE moved to SHARE, and GUIDE suggested to its members that they join SHARE. In August 2000, SHARE took over the guide.org domain name.
In 2005 SHARE's membership of 20,000 represented some 2,300 enterprise IBM customers.[7]
Edson, Joanne; Greenstadt, John; Greenwald, Irwin; Jones, Fletcher R.; Wagner, Frank V., eds. (1959-04-15) [August 1956]. SHARE Reference Manual for the IBM 704(PDF). Archived(PDF) from the original on 2012-03-04. Retrieved 2020-06-16.