The array-programming languages chapter operates as a sub-group of ACM's SIGPLAN: the Special Interest Group on Programming LANguages.

Upcoming APL & Functional Programming Events

NYCJUG Meeting - Tuesday, July 11th, 2023, 18:30 EDT

The New York City J Users Group will hold its regular online monthly meeting on Tuesday, July 11th at 6:30 pm EDT. Please take a look at our Meetup site for further information. To see notes on this and other past meetings, take a look at our meeting notes .

ArrayCast - the array languages podcast

This hour long podcast has many episodes, including interviews with numerous notable people in the array-language community.

The APL Show

Inspired by Ken Iverson's paper ''Notation as Tool of Thought", this podcast explores various aspects of notation in the context of the APL programming languages.

APL Quest - Fridays at 15:00 UTC

Work through solutions from the Dyalog APL Problem Solving Competition; look here for more information.

Semi-Regular Thursday APL Meetings

Nearly every Thursday at 16:00 UTC, either the British APL Association or Dyalog has a meeting or webinar. For more information, look here for the BAA and here for Dyalog.

SIGPLAN-sponsored Conferences

The ACM Special Interest Group on Programming Languages sponsors a number of conferences. For more information, look here.

Various Functional Programming Events

Look here for "the ultimate", though it is Clojure-centric, list of upcoming meetings for functional programming languages.

Recent Events Relevant to APL and Other Functional Languages

APLBUG - Monday, June 19th, 2023

The Bay Area Users Group hosted Data I/O, a discussion with Richard Park of Dyalog about moving data in and out of APL workspaces. Officers of APLBUG were also elected at this meeting. More information may be found here.

Kx Con - May 17-20, 2023

This conference for the K & Q languages is called ''The Time Series Data & AI Summit''. It was held in Montauk, NY, USA. A retrospective on the conference may be found here.

NYCJUG Meeting - Tuesday, June 13th, 2023, 18:30 EDT

The New York City J Users Group held its regular online monthly meeting on Tuesday, June 13th at 6:30 pm EDT. To see notes on this and other past meetings, take a look at our meeting notes .

Vector Webinar, April 20th, 2023

The British APL Association held an open session webinar on Thursday, April 20th, 2023 at 16:00 BST (UTC+1). Look here for more information.

APL BUG Round-Table Discussion - April 10th, 2023, 17:00 UTC

The Bay Area Users Group has scheduled an open discussion at this time. More information may be found here.

APL Seeds - Wednesday, March 22nd, 2023

This event was for those just starting their APL journey. It was held online and materials covered can be found here.

NYCJUG Meeting - Tuesday, March 14th, 2023, 18:30 EDT

The New York City J Users Group held its regular online monthly meeting on Tuesday, March 14th at 6:30 pm EDT. Please sign up on our meetup page to get the link to this online event and take a look at our meeting notes .

APL Campfire with Norman Thomson - Sunday, March 12th, 2023

This meeting focuses on the history of APL programming, inviting participants to tell stories in an informal setting. More information and notes on past meetings can be found here.

Vector Webinar - Thursday, March 9th, 2023, 16:00 GMT

This open session was sponsored by the British APL Association. The schedule of webinars and information on how to join them can be found here.

Forth Day 2022 - Saturday, November 19th, 2022

For more infomation on this meeting, look here.

APLBUG Meeting November 14th, 2022, 10:00 PST

The APL Bay Area Users' Group will have a round-table discussion on Zoom at 10 am Pacific time to discuss various APL topics. More information may be found here.

Dyalog '22 - October 9th-13th, 2022

Dyalog Ltd. resumed in-person meetings with this October conference in Olhão, Portugal. More information may be found here.

Vintage Computer Festival West - Sunday, August 7th, 2022

This festival was held at the Computer History Museum, in Mountain View, California. For more information, look here.

ARRAY 2022 - Monday, June 13th, 2022

This one-day workshop explored the following aspects of array-oriented programming: formal semantics and design issues of array languages, productivity and performance, systematic notation, efficient mappings onto various kinds of CPUs, and more. More information may be found here.

APLBUG Meeting May 8th, 2022, 11:00 PDT

The APL Bay Area Users' Group, the Northern California APL ACM Chapter, joined the APL Campfire on the 8th of May at 11 am Pacific time to hear Paul Jackson describe his experiences with APL. More information may be found here.
APL Campfire featuring Paul Jackson

Lambda Days - February 10th-11th, 2022

The next "Lambda Days" conference will take place in Kraków, Poland on February 10th-11th, 2022. This is where academia meets industry! Find out more information here.

Principles of Programming Languages conference - January 16th-22nd, 2022

POPL’22 was held in Philadelphia from Sunday, January 16 to Saturday, January 22, 2022, in Westin Philadelphia in Rittenhouse Square in Center City. Look here for more information.


In Memoriam - Linda Alvord

The APL community is saddened to hear of the passing of Linda Alvord, a long-time educator and contributor to applications of APL.

Dyalog APL Competition now open!

They annual APL Problem Solving Competition is now open. There are two phases to the competition. The first phase consists of ten problems which must all be solved; the second phase consists of more complex problems that do not all have to be solved. For more information and a list of the problems and solutions from past competitions, take a look at the competition's home page.

Array Cast

This series of pod-casts discusses array programming languages, usually with a different guest from the array-languages community. The hour-long episodes are listed here.

APL2000 announces APL64.

The initial production version of APL64 is expected to be released in July 2022. More information may be found here.

Log-On announces APL2 GA v. 3.03

The latest GA version 3.03 of Log-On APL2 for workstations introduced support for HTTPS websites and successfully tested the version on WINDOWS 11. Please contact ''Log-On'' at for details on how to receive the new version, or look here.

Term-Rewriting in K

This project implements simple unconditional term-rewriting with examples from elementary logic using an elegant k6 implementation of limited symbolic unification.

One problem solved in six languages

This video compares solutions to a simple problem coded in six different languages - C++ (4 versions), Rust, Clojure, Scala, Haskell, and APL - by a professional C++ programmer.

J version 9.03 Released

The latest stable version of the J language, 9.03, is freely downloadable. This version introduces name reference caching, compensated summation (to improve accuracy of addition), computations with twice the precision of normal floating point, and other efficiency improvements. Look here for more information. J is available for these platforms:
  • Windows
  • Mac OS X
  • Linux
  • iOS
  • Android
  • Raspberry Pi
  • New Paper: The Derivative Revisited

    This paper revisits much of Ken Iverson's 1979 paper on derivatives, from differential calculus, of the most general type, bringing the notation up to date. It also provides an APL model of the derivative operator.

    Essays and J Code from Keith Smillie

    The late Keith Smillie published a number of works and associated code on learning J and implementing various statistical calculations in it as well. Some of them are here.

    Fun Q book on machine learning using q now available

    The book "Fun Q: A Functional Introduction to Machine Learning in Q", by Nick Psaris, covers many topics in machine learning with q code provided. More information on the book, the q language, and the machine learning code may be found here.

    Shakti Youtube Channel Launched

    Shakti has started a Youtube channel with Meetup talks and an installation tutorial to learn more about k9.

    New version of k available from Shakti

    A new and different version of k, called "k9", is available for download from Shakti. It currently is available for MacOS and Linux.

    Dyalog Version 18.0 Now Available

    Version 18.0 of Dyalog APL is available on all supported platforms. This release includes significant performance improvements, a bridge to Microsoft's .NET core, new APL primitives, and more. Look here for more details.

    Mesh: a spreadsheet programmable with an array language

    This code editor that feels like a spreadsheet supports APL and k. There is a video introduction to Mesh using Shakti.

    Minimal introduction to k

    Here is a very brief introduction to the k language.

    APL+Win C# Script Engine Released

    This latest 19.0 version of the APL2000 product line makes available this C# interface to subscribers. See this for more details.

    Run APL in a browser and use APL in web-page development

    Paul L. Jackson's browser-based APL can be installed locally and used to design, display, and test web pages from the APL development environment.

    John Scholes, in memoriam

    We are sad to report that the inimitable John Scholes passed away recently. He is remembered fondly by the APL community, not the least because of his many engaging appearances, some of which are available online, particularly his Plea for Simplicity, his tutorial on how to deal with distractions while programming, and Social Skills for Programmers.

    Dyalog 2018 Videos

    Videos of some of the talks at Dyalog '18, held in Belfast, Northern Ireland, from October 28th through November 1st, are available here.

    New Release of Eli: Compiled APL

    "ELI", a system for programming with arrays, with most of the functionality of ISO APL but with extended data types like non-homogenous arrays, complex numbers, and temporal data, is freely available on Windows, Linux, and Mac OS. The language has a compiler as well as an interpreter and SQL statements. Visit the Eli homepage and take a look at this article in Vector for more details.

    Source of JavaScript Implementation of APL Available on Github

    The source code for the above-mentioned implementation of APL - "NGN APL" - that will run in a browser, is here. It is written in CoffeeScript, a language that "compiles" to JavaScript.

    Gnu Open-source APL Released

    GNU APL is a free interpreter for which the source code is available. It is written and is being maintained by Jürgen Sauermann under a Gnu license. It is aimed at a Linux environment but compiles under Cygwin for a Windows environment.

    Waterloo APL Archive

    The Waterloo APL Archive has been resurrected here. These links have not been tested thoroughly, so please report any problems to us.

    Graphical J Sentence Analyzer

    Announcing a graphical sentence debugger for J: wouldn't it be great if you could actually see how a sentence executes? Instead of puzzling over some expressions like this:
       z =. 100 200 300
       +/ z + i. 3 3
    609 612 615
    you can see a picture like this:

    graphical representation of a J phrase

    APL Fonts

    Many APL fonts