Editing APL (programming language) (section)

=== Commercial availability ===
The first APL interactive login and creation of an APL workspace was in 1966 by Larry Breed using an IBM 1050 terminal at the IBM Mohansic Labs near [[Thomas J. Watson Research Center]], the home of APL, in [[Yorktown Heights]], New York.<ref name="APLQQ91"/>

IBM was chiefly responsible for introducing APL to the marketplace. The first publicly available version of APL was released in 1968 for the [[IBM 1130]]. IBM provided ''APL\1130'' for free but without liability or support.<ref>{{cite journal |url=http://www.vector.org.uk/archive/v223/APL_1130.htm |title=How We Got to APL\1130 |last1=Breed |first1=Larry |author-link=Larry Breed |journal=Vector (British APL Association) |volume=22 |issue=3 |date=August 2006 |issn=0955-1433 |access-date=2007-04-02 |archive-url=https://web.archive.org/web/20080512031437/http://www.vector.org.uk/archive/v223/APL_1130.htm |archive-date=2008-05-12 |url-status=dead}}</ref><ref>[http://bitsavers.org/pdf/ibm/1130/lang/1130-03.3.001_APL_1130_May69.pdf APL\1130 Manual] {{Webarchive|url=https://web.archive.org/web/20110221034650/http://www.bitsavers.org/pdf/ibm/1130/lang/1130-03.3.001_APL_1130_May69.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.bitsavers.org/pdf/ibm/1130/lang/1130-03.3.001_APL_1130_May69.pdf |archive-date=2022-10-09 |url-status=live |date=2011-02-21}}, May 1969</ref> It would run in as little as 8k 16-bit words of memory, and used a dedicated 1 megabyte hard disk.

APL gained its foothold on mainframe timesharing systems from the late 1960s through the early 1980s, in part because it would support multiple users on lower-specification systems that had no [[Memory management unit|dynamic address translation]] hardware.<ref>{{cite web|url=http://www.quadibloc.com/comp/aplint.htm |title=Remembering APL |publisher=Quadibloc.com |access-date=June 17, 2013}}</ref> Additional improvements in performance for selected [[IBM System/370]] mainframe systems included the ''APL Assist Microcode'' in which some support for APL execution was included in the processor's [[firmware]], as distinct from being implemented entirely by higher-level software. Somewhat later, as suitably performing hardware was finally growing available in the mid- to late-1980s, many users migrated their applications to the personal computer environment.

Early IBM APL interpreters for IBM 360 and IBM 370 hardware implemented their own multi-user management instead of relying on the host services, thus they were their own timesharing systems. First introduced for use at IBM in 1966, the ''APL\360''<ref name="IBM APL\360 1968">Falkoff, Adin; Iverson, Kenneth E., [http://bitsavers.org/pdf/ibm/apl/APL_360_Users_Manual_Aug68.pdf "APL\360 Users Guide"] {{Webarchive|url=https://web.archive.org/web/20120229200744/http://bitsavers.org/pdf/ibm/apl/APL_360_Users_Manual_Aug68.pdf |date=2012-02-29}}, IBM Research, Thomas J. Watson Research Center, Yorktown Heights, NY, August 1968.</ref><ref>[http://bitsavers.org/pdf/ibm/apl/APL_360_Terminal_System_Mar67.pdf "APL\360 Terminal System"] {{Webarchive|url=https://web.archive.org/web/20100711092528/http://bitsavers.org/pdf/ibm/apl/APL_360_Terminal_System_Mar67.pdf |date=2010-07-11}}, IBM Research, Thomas J. Watson Research Center, March 1967.</ref><ref name="apl360">{{cite book |last1=Pakin |first1=Sandra |title=APL\360 Reference Manual |publisher=Science Research Associates, Inc. |year=1968 |isbn=978-0-574-16135-2}}</ref> system was a multi-user interpreter. The ability to programmatically communicate with the operating system for information and setting interpreter system variables was done through special privileged "I-beam" functions, using both [[Monad (functional programming)|monadic]] and [[Dyadics|dyadic]] operations.<ref>Falkoff, Adin D.; Iverson, Kenneth E.,[http://www.research.ibm.com/journal/rd/174/ibmrd1704F.pdf ''The Design of APL''], ''IBM Journal of Research and Development'', Volume 17, Number 4, July 1973. "These environmental defined functions were based on the use of still another class of functions—called "I-beams" because of the shape of the symbol used for them—which provide a more general facility for communication between APL programs and the less abstract parts of the system. The I-beam functions were first introduced by the system programmers to allow them to execute System/360 instructions from within APL programs, and thus use APL as a direct aid in their programming activity. The obvious convenience of functions of this kind, which appeared to be part of the language, led to the introduction of the monadic I-beam function for direct use by anyone. Various arguments to this function yielded information about the environment such as available space and time of day."</ref>

In 1973, IBM released ''APL.SV'', which was a continuation of the same product, but which offered [[shared variable]]s as a means to access facilities outside of the APL system, such as operating system files. In the mid-1970s, the IBM mainframe interpreter was even adapted for use on the [[IBM 5100]] desktop computer, which had a small CRT and an APL keyboard, when most other small computers of the time only offered [[BASIC]]. In the 1980s, the ''VSAPL'' [[Software as a Product|program product]] enjoyed wide use with [[Conversational Monitor System]] (CMS), [[Time Sharing Option]] (TSO), [[VSPC]], [[MUSIC/SP]], and [[CICS]] users.

In 1973–1974, Patrick E. Hagerty directed the implementation of the University of Maryland APL interpreter for the 1100 line of the Sperry [[UNIVAC 1100/2200 series]] mainframe computers.<ref>{{cite report |last1=Minker |first1=Jack |title=Beginning of Computing and Computer Sciences at the University of Maryland |url=http://www.cs.umd.edu/department/dept-history/minker-report.pdf |publisher=University of Maryland |access-date=May 23, 2011 |section=2.3.4 Computer Software Developments in the CSC, 1962–1973 |page=38 |date=January 2004 |archive-url= https://web.archive.org/web/20110610064807/http://www.cs.umd.edu/department/dept-history/minker-report.pdf |archive-date= June 10, 2011}}</ref>  In 1974, student Alan Stebbens was assigned the task of implementing an internal function.<ref>{{cite web |last1=Stebbens |first1=Alan |title=How it all began |url=http://lathwellproductions.ca/wordpress/film |access-date=2011-05-22 |archive-url=https://web.archive.org/web/20160304000314/http://lathwellproductions.ca/wordpress/film |archive-date=2016-03-04 |url-status=dead}}</ref> Xerox APL was available from June 1975 for Xerox 560 and Sigma 6, 7, and 9 mainframes running [[Universal Time-Sharing System#CP-V|CP-V]] and for [[Honeywell CP-6]].<ref>{{cite web |title=Xerox APL Language and Operations Reference Manual |url=http://www.softwarepreservation.org/projects/apl/Books/197506_Xerox%20APL%20Language%20and%20Operations%20Reference%20Manual_90131C.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.softwarepreservation.org/projects/apl/Books/197506_Xerox%20APL%20Language%20and%20Operations%20Reference%20Manual_90131C.pdf |archive-date=2022-10-09 |url-status=live}}</ref>

In the 1960s and 1970s, several timesharing firms arose that sold APL services using modified versions of the IBM APL\360<ref name="apl360"/> interpreter. In North America, the better-known ones were [[IP Sharp Associates]], [[Scientific Time Sharing Corporation]] (STSC), Time Sharing Resources (TSR), and [[The Computer Company]] (TCC). CompuServe also entered the market in 1978 with an APL Interpreter based on a modified version of Digital Equipment Corp and Carnegie Mellon's, which ran on DEC's KI and KL 36-bit machines. CompuServe's APL was available both to its commercial market and the consumer information service. With the advent first of less expensive mainframes such as the [[IBM 4300]], and later the personal computer, by the mid-1980s, the timesharing industry was all but gone.

''Sharp APL'' was available from IP Sharp Associates, first as a timesharing service in the 1960s, and later as a program product starting around 1979. ''Sharp APL'' was an advanced APL implementation with many language extensions, such as ''packages'' (the ability to put one or more objects into a single variable), a file system, nested arrays, and [[shared variable]]s.

APL interpreters were available from other mainframe and mini-computer manufacturers also, notably [[Burroughs Corporation|Burroughs]], [[Control Data Corporation]] (CDC), [[Data General]], [[Digital Equipment Corporation]] (DEC), [[Harris Corporation|Harris]], [[Hewlett-Packard]] (HP), [[Siemens]], [[Xerox]] and others.

Garth Foster of [[Syracuse University]] sponsored regular meetings of the APL implementers' community at Syracuse's Minnowbrook Conference Center in [[Blue Mountain Lake (hamlet), New York|Blue Mountain Lake, New York]]. In later years, Eugene McDonnell organized similar meetings at the [[Asilomar Conference Grounds]] near [[Monterey]], [[California]], and at Pajaro Dunes near [[Watsonville]], California. The SIGAPL special interest group of the [[Association for Computing Machinery]] continues to support the APL community.<ref>{{cite web |url=http://www.sigapl.org/ |title=SIGAPL |publisher=Sigapl.org |access-date=June 17, 2013}}</ref>