Editing APL (programming language) (section)

=== APL2 ===
Starting in the early 1980s, IBM APL development, under the leadership of [[Jim Brown (computer scientist)|Jim Brown]], implemented a new version of the APL language that contained as its primary enhancement the concept of ''nested arrays'', where an array can contain other arrays, and new language features which facilitated integrating nested arrays into program workflow. Ken Iverson, no longer in control of the development of the APL language, left IBM and joined [[I. P. Sharp Associates]], where one of his major contributions was directing the evolution of Sharp APL to be more in accord with his vision.<ref>{{cite web |last1=Hui |first1=Roger |title=Remembering Ken Iverson |url=http://keiapl.org/rhui/remember.htm|archive-url=https://archive.today/20130415054224/http://keiapl.org/rhui/remember.htm|url-status=usurped|archive-date=April 15, 2013|website=keiapl.org|publisher=KEIAPL |access-date=January 10, 2015}}</ref><ref>{{cite web |website=ACM A.M. Turing Award |title=Kenneth E. Iverson |url=http://amturing.acm.org/award_winners/iverson_9147499.cfm |publisher=ACM |access-date=January 10, 2015}}</ref><ref>{{cite web |title=APL2: The Early Years: Can you and should you compromise on technical issues? |website=SIGPLAN Chapter on Array-Programming Languages |url=http://www.sigapl.org/Articles/JimBrown-TechCompromise.php |publisher=ACM |access-date=January 10, 2015}}</ref> APL2 was first released for [[Conversational Monitor System|CMS]] and [[Time Sharing Option|TSO]] in 1984.<ref name="FalkoffIBMFamily">{{cite journal |title=The IBM family of APL systems |first1=Adin D. |last1=Falkoff |s2cid=19030940 |year=1991 |journal=IBM Systems Journal |volume=30 |issue=4 |pages=416–432 |doi=10.1147/sj.304.0416}}</ref> The APL2 Workstation edition (Windows, [[OS/2]], [[IBM AIX|AIX]], [[Linux]], and [[Solaris (operating system)|Solaris]]) followed later.<ref>{{cite web |url=http://www.edm2.com/index.php/IBM_APL2 |title=IBM APL2 |website=EDM2 |date=2019-10-09 |access-date=2021-11-17 |archive-date=2021-11-17 |archive-url=https://web.archive.org/web/20211117121942/http://www.edm2.com/index.php/IBM_APL2 |url-status=dead}}</ref><ref>{{cite web |title=APL2: What's New |url=http://www-01.ibm.com/support/docview.wss?uid=swg22012321 |website=ibm.com |publisher=IBM |access-date=April 22, 2018}}</ref>

As other vendors were busy developing APL interpreters for new hardware, notably [[Unix]]-based [[microcomputer]]s, APL2 was almost always the standard chosen for new APL interpreter developments. Even today, most APL vendors or their users cite APL2 compatibility as a selling point for those products.<ref>{{cite web|last1=Micro APL|title=Overview of the APL System |url=https://microapl.com/apl/apl_concepts_chapter1.html |website=microapl.com|publisher=Micro APL|access-date=January 10, 2015}}</ref><ref>{{cite web |last1=Robertson |first1=Graeme |title=A Personal View of APL2010 |url=http://archive.vector.org.uk/art10500450|website=archive.vector.org.uk |publisher=Vector – Journal of the British APL Association |access-date=January 10, 2015 |archive-url=https://web.archive.org/web/20150402093211/http://archive.vector.org.uk/art10500450 |archive-date=April 2, 2015 |url-status=dead}}</ref> IBM cites its use for problem solving, system design, prototyping, engineering and scientific computations, expert systems,<ref>{{cite journal |last1=Rodriguez |first1=P. |last2=Rojas |first2=J. |last3=Alfonseca |first3=M. |last4=Burgos |first4=J. I. |title=An Expert System in Chemical Synthesis written in APL2/PC |journal=ACM SIGAPL APL Quote Quad |date=1989 |volume=19 |issue=4 |pages=299–303 |doi=10.1145/75144.75185 |s2cid=16876053}}</ref> for teaching mathematics and other subjects, visualization and database access.<ref>{{cite web |title=APL2: A Programming Language for Problem Solving, Visualization and Database Access|url=http://www-03.ibm.com/software/products/en/apl2|archive-url=https://web.archive.org/web/20131122133145/http://www-03.ibm.com/software/products/en/apl2|url-status=dead|archive-date=November 22, 2013|website=www-03.ibm.com|publisher=IBM|access-date=January 10, 2015}}</ref>