Update 1/1/2016: Gordon Bell has made an archive of materials from The Computer Museum available at https://tcm.computerhistory.org.
The institution now known as the Computer History Museum began in 1975 as a closet-sized exhibit in a Digital Equipment Corporation building, grew into The Computer Museum located on Boston’s Museum Wharf, and finally metamorphosed into its current form and location. In a fascinating technical report, Gordon Bell describes this long and interesting history, in which he and his wife Dr. Gwen Bell have played such important roles.
It was only recently, Bell notes, that “Software was finally added to list of things collected, such as the history of FORTRAN including original source code.” The FORTRAN collection to which Gordon refers is here; a catalog search of FORTRAN-related items in the museum’s archives is available here.
Bell gives a list of some two dozen “Mona Lisas” in the collection, all hardware artifacts. He concludes this section by saying “Regrettably, I omit that hard to see, hard to describe, essential software from COBOL, FORTRAN, and LISP, various Operating Systems, and on through Visicalc, and the Relational database.” I strongly agree with Bell about the importance of collecting and displaying such historic software. I’m glad to be able to point the previously-mentioned FORTRAN collection, and to similar collections for LISP, ALGOL, and C++. Others have assembled extensive collections on, for example, the Multics and Unix operating systems, PDP-10 systems and applications, and many more. Two of the earliest relational database management systems, Berkeley Ingres and IBM System R, have been preserved but are not yet easily accessible. For the most part, these collections are aimed at a more scholarly audience; I hope they will serve as source materials for future exhibits for a wider audience.
Update 2024/05/08: Updated various URLs.