IBM Type-III Library
| Company type | Software library |
|---|---|
| Industry | Computer software |
| Founded | 1960s |
| Founder | IBM employees |
| Headquarters | Hawthorne , United States |
Area served | IBM clients |
| Products | Software programs (e.g., GPSS, APL, CP/CMS, HASP, JOVIAL compiler, CPS) |
The IBM Type-III Library (also referred to as Type-III software or Type-III product) consisted of software IBM provided to its clients free of charge, without any warranties, support, or liability, and was generally distributed in source-code form. Although this classification is most commonly associated with mainframe software, IBM extended the Type-III designation to software for smaller-scale systems as well.
IBM also made other operating systems available in source code format. In the early days, many operating systems were delivered this way. The VM family continued to be distributed in source form for many years after it succeeded CP/CMS from the Type-III Library, and the TPF system was consistently provided as source code—a practice that persists with z/TPF. Unlike Type-III offerings, these particular systems received IBM support.
Scope of the IBM Program Libraries
Throughout the mainframe period, IBM categorized its software offerings into two primary groups. The first group consisted of IBM-developed and supported products: Type I (Programming Systems) and Type II (Application Programs), both of which underwent formal testing and maintenance by IBM.
The second group encompassed Type III and Type IV programs. Type III (IBM Contributed Programs) and Type IV (Customer Contributed Programs) were submitted to IBM’s Program Information Department (PID) for distribution but did not receive formal testing or modifications.
These collections were overseen by IBM’s Program Information Department located in Hawthorne, New York, with distribution operations handled from Mechanicsburg, Pennsylvania. Separate catalogs were issued for each compatible IBM processor family.
- An IBM document regarding CP/CMS characterized Type-III software as "IBM employee contributed" and stated:
[This software] has not been subject to formal testing. Type III Programs are offered as a service to customers, who must assess their suitability independently. No guaranteed maintenance or warranty is provided concerning documentation, functionality, or performance.
Originally made available at no cost as part of IBM’s service offerings, the Type-III library underwent changes following IBM’s 1969 “unbundling” initiative, which separated pricing for hardware, software, and services. Subsequently, the library was replaced by new classifications: customer-submitted programs became known as "Installed User Programs" (IUPs), while those created by IBM employees were labeled "Field Developed Programs" (FDPs). Despite this terminology, many FDPs originated within IBM programming teams rather than from field staff.
Products
Among the notable software products classified under IBM’s Type-III designation are:
- 1961: General Purpose Simulation System (GPSS)
- 1968: APL programming language designed for the IBM 1130 and System/360 computers
- May 1968: CP/CMS operating system
- Houston Automatic Spooling Priority (HASP)
- JOVIAL compiler
- August 1969: Conversational Programming System (CPS)
These examples illustrate IBM’s strategic focus on developing programming languages and system software that complemented its hardware platforms and advanced enterprise computing functions.
References