Editing Logo (programming language)

{{Short description|Computer programming language}}
{{Infobox programming language
| name = Logo
| logo = 
| logo caption = 
| screenshot = KochTurtleAnim.gif
| screenshot caption = [[L-system#Example 4: Koch curve|L-system (Koch curve)]] turtle graphic
| paradigms = [[Multi-paradigm programming language|Multi-paradigm]]: [[Functional programming|functional]], [[Educational programming language|educational]], [[Procedural programming|procedural]], [[Reflective programming|reflective]]
| family = [[Lisp (programming language)|Lisp]]
| designers = [[Wally Feurzeig]], [[Seymour Papert]], [[Cynthia Solomon]]
| developer = [[BBN Technologies|Bolt, Beranek and Newman]]
| released = {{Start date and age|1967}}
| typing = [[Dynamic typing|dynamic]]
| implementations = [[UCBLogo]], many others
| dialects = [[StarLogo]], [[NetLogo]] and [[AppleLogo]]
| influenced = [[AgentSheets]], [[NetLogo]], [[Smalltalk]], [[Etoys (programming language)|Etoys]], [[Scratch (programming language)|Scratch]], [[Microsoft Small Basic]], KTurtle, [[REBOL]], [[Boxer (programming environment)|Boxer]]
| influenced by = [[Lisp (programming language)|Lisp]]
}}
[[File:Remi_turtlegrafik.png|thumb|Symmetry around a point can be obtained using only a few instructions, allowing users to draw [[hypotrochoid]]s like the one shown here.]]
'''Logo''' is an [[list of educational programming languages|educational programming language]], designed in 1967 by [[Wally Feurzeig]], [[Seymour Papert]], and [[Cynthia Solomon]].<ref>{{Cite journal |url=https://dspace.mit.edu/handle/1721.1/6226 |title=Logo Manual |last1=Abelson |first1=Hal |last2=Goodman |first2=Nat |date=December 1974 |website=Artificial Intelligence Lab, Massachusetts Institute of Technology |access-date=August 28, 2016 |last3=Rudolph |first3=Lee |hdl=1721.1/6226 |url-status=live |archive-url=https://web.archive.org/web/20160911020834/https://dspace.mit.edu/handle/1721.1/6226 |archive-date=September 11, 2016 }}</ref> The name was coined by Feurzeig while he was at [[Raytheon BBN|Bolt, Beranek and Newman]],<ref name="goldenberg198208">{{cite news |url=https://archive.org/stream/byte-magazine-1982-08/1982_08_BYTE_07-08_Logo#page/n209/mode/2up |title=Logo – A Cultural Glossary |last=Goldenberg |first= E. Paul |date=August 1982 |work=Byte |access-date=19 October 2013|pages=218}}</ref> and derives from the Greek ''logos'', meaning 'word' or 'thought'.

A general-purpose language, Logo is widely known for its use of [[turtle graphics]], in which commands for movement and drawing produced line or [[vector graphics]], either on screen or with a small robot termed a [[Turtle (robot)|turtle]]. The language was conceived to teach concepts of programming related to [[Lisp (programming language)|Lisp]] and only later to enable what Papert called "[[Proprioception|body-syntonic]] reasoning", where students could understand, predict, and reason about the turtle's motion by imagining what they would do if they were the turtle. There are substantial differences among the many dialects of Logo, and the situation is confused by the regular appearance of turtle graphics programs that are named Logo.

Logo is a [[Comparison of multi-paradigm programming languages|multi-paradigm]] adaptation and dialect of Lisp, a [[functional programming]] language.<ref name=cslsPreface >CSLS Vol 1, Preface .pxvi, Harvey 1997</ref> There is no standard Logo, but [[UCBLogo]] has the facilities for handling lists, files, I/O, and [[Recursion (computer science)|recursion]] in scripts, and can be used to teach all computer science concepts, as [[University of California, Berkeley|UC Berkeley]] lecturer [[Brian Harvey (lecturer)|Brian Harvey]] did in his ''Computer Science Logo Style'' trilogy.<ref name=csls>''Computer Science Logo Style'', Brian Harvey, MIT Press (3 volumes) {{ISBN|0-262-58148-5}}, {{ISBN|0-262-58149-3}}, {{ISBN|0-262-58150-7}}. Available [http://www.cs.berkeley.edu/~bh/ online] {{webarchive |url=https://web.archive.org/web/20130704014342/http://www.cs.berkeley.edu/~bh/ |date=2013-07-04 }}</ref>

Logo is usually an [[Interpreter (computing)|interpreted language]], although compiled Logo dialects (such as Lhogho and Liogo) have been developed. Logo is not case-sensitive but retains the case used for formatting purposes.

==History==
Logo was created in 1967 at [[Bolt, Beranek and Newman]] (BBN), a [[Cambridge, Massachusetts]], research firm, by [[Wally Feurzeig]], [[Cynthia Solomon]], and [[Seymour Papert]].<ref name="mit.edu">{{cite web |url=http://el.media.mit.edu/logo-foundation/index.html |title=Logo Foundation |website=el.media.mit.edu |url-status=dead |archive-url=https://web.archive.org/web/20110721122057/http://el.media.mit.edu/logo-foundation/index.html |archive-date=2011-07-21 |access-date=2011-04-07 }}</ref> Its intellectual roots are in [[artificial intelligence]], [[mathematical logic]] and [[developmental psychology]]. For the first four years of Logo research, development and teaching work was done at BBN. The first implementation of Logo, called Ghost, was written in [[LISP]] on a [[PDP-1]]. The goal was to create a mathematical land where children could play with words and sentences.<ref>{{cite web |url=https://logothings.wikispaces.com/ |title=logothings |website=logothings.wikispaces.com |url-status=live |archive-url=https://web.archive.org/web/20111207111525/http://logothings.wikispaces.com/ |archive-date=2011-12-07 }}</ref> Modeled on LISP, the design goals of Logo included accessible power{{Clarify |date=March 2008}} <!-- what kinda of power? --> and informative error messages. The use of virtual [[Turtle (robot)|Turtles]] allowed for immediate visual feedback and debugging of graphic programming.

The first working Logo turtle robot was created in 1969. A display turtle preceded the physical floor turtle. Modern Logo has not changed very much from the basic concepts predating the first turtle. The first turtle was a tethered floor roamer, not [[radio-control]]led or [[wireless]]. At BBN Paul Wexelblat developed a turtle named Irving that had touch sensors and could move forwards, backwards, rotate, and ding its bell. The earliest year-long school users of Logo were in 1968–69 at Muzzey Jr. High in [[Lexington, Massachusetts]]. The virtual and physical turtles were first used by fifth-graders at the Bridge School in the same city in 1970–71.

==Turtle and graphics==
{{see also|Turtle graphics}}
[[File:Tartapelago Bicicardio 01.gif|thumb|upright=1| Animated gif with turtle in [[MSWLogo]] ([[Cardioid]])<ref>{{cite web|url=https://www.maecla.it/tartapelago.htm |title=Tartapelago|first=Giorgio|last=Pietrocola |date=2005 |website=Maecla  }}</ref>]]
Logo's most-known feature is the turtle (derived originally from [[Turtle (robot)|a robot of the same name]]),<ref name="mit.edu"/> an on-screen "[[Pointer (graphical user interfaces)|cursor]]" that shows output from commands for movement and small retractable pen, together producing line graphics. It has traditionally been displayed either as a triangle or a turtle icon (though it can be represented by any icon). Turtle graphics were added to the Logo language by Seymour Papert in the late 1960s to support Papert's version of the turtle robot, a simple robot controlled from the user's workstation that is designed to carry out the drawing functions assigned to it using a small retractable pen set into or attached to the robot's body.

As a practical matter, the use of turtle geometry instead of a more traditional model mimics the actual movement logic of the turtle robot. The turtle moves with commands that are relative to its own position, ''LEFT 90'' means spin left by 90 degrees. Some Logo implementations, particularly those that allow the use of concurrency and multiple turtles, support [[collision detection]] and allow the user to redefine the appearance of the turtle cursor, essentially allowing the Logo turtles to function as [[Sprite (computer graphics)|sprites]].

Turtle geometry is also sometimes used in environments other than Logo as an alternative to a strictly coordinate-addressed graphics system. For instance, the idea of turtle graphics is also useful in [[Lindenmayer system]] for generating [[fractal]]s.

== Implementations ==
{{anchor|DrLogo}} <!--The page Dr. Logo redirects here-->
{{Redirect|Apple Logo|the logo of Apple Inc.|Apple logo}}
[[File:IBM LCSI Logo Welcome Screen.png|thumb|IBM LCSI Logo welcome screen]]
[[File:IBM LCSI Logo Circles.png|thumb|Source code and output in IBM LCSI Logo]]

Some modern derivatives of Logo allow thousands of independently moving turtles. There are two popular implementations: [[Massachusetts Institute of Technology]]'s [[StarLogo]] and [[Northwestern University]] Center for Connected Learning's (CCL) [[NetLogo]]. They allow exploring [[emergence|emergent phenomena]] and come with many experiments in social studies, biology, physics, and other areas. NetLogo is widely used in agent-based simulation in the biological and social sciences.

Although there is no agreed-upon standard, there is a broad consensus on core aspects of the language. In March 2020, there were counted 308 implementations and dialects of Logo, each with its own strengths.<ref>{{cite web |url=https://pavel.it.fmi.uni-sofia.bg/logotree/pdf/LogoTree.pdf |title=The Logo Tree Project |website=elica.net |url-status=dead |archive-url=https://web.archive.org/web/20090306084150/http://elica.net/download/papers/LogoTreeProject.pdf |archive-date=2009-03-06 |access-date=2020-03-25 }}</ref> Most of those 308 are no longer in wide use, but many are still under development. Commercial implementations widely used in schools include ''[[MicroWorlds]] Logo'' and ''Imagine Logo''.

Legacy and current implementations include:

; First released in 1980s:
* Apple Logo for the [[Apple II Plus]] and Apple Logo Writer for the [[Apple IIe]], developed by Logo Computer Systems, Inc. (LCSI), were the most broadly used and prevalent early implementations of Logo that peaked in the early to mid-1980s.
* Aquarius LOGO was released in 1982 on cartridge by [[Mattel]] for the [[Mattel Aquarius|Aquarius]] home computer.
* [[Atari Logo]], developed by LCSI, was released on cartridge by [[Atari Inc|Atari, Inc.]] in 1983 for the [[Atari 8-bit computers]].
* Color Logo was released in 1983 on cartridge (26–2722) and disk (26–2721) by [[Tandy Corporation|Tandy]] for the [[TRS-80 Color Computer]].
* Commodore Logo was released, with the subtitle "A Language for Learning", by [[Commodore International]]. It was based on MIT Logo and enhanced by Terrapin, Inc. The [[Commodore 64]] version (C64105) was released on diskette in 1983; the [[Commodore Plus/4|Plus/4]] version (T263001) was released on cartridge in 1984.<ref>{{cite web |url=http://www.zimmers.net/commie/docs/cbm-products.txt |title=Canonical List of Commodore Products |date=2017-10-30 |access-date=2017-12-03 |last1=Brain |first1=Jim |last2=Zimmerman |first2=Bo |url-status=live |archive-url=https://web.archive.org/web/20171220005631/http://www.zimmers.net/commie/docs/cbm-products.txt |archive-date=2017-12-20 }}</ref><ref>{{cite web |url=http://plus4world.powweb.com/software/Logo |title=Logo – Software Details |website=Plus/4 World |access-date=2017-12-03 |url-status=live |archive-url=https://web.archive.org/web/20171204171250/http://plus4world.powweb.com/software/Logo |archive-date=2017-12-04 }}</ref>
* SmartLOGO was released on cassette by [[Coleco]] for the [[Coleco ADAM|ADAM]] home computer in 1984.  It was developed by LCSI and included a primer, ''Turtle Talk'', by Seymour Papert.
* ExperLogo was released in 1985 on diskette by Expertelligence Inc. for the [[Macintosh 128K]].
* Hot-Logo was released in the mid-1980s by EPCOM for the [[MSX]] 8-bit computers with its own set of commands in Brazilian Portuguese.
* TI Logo (for the [[TI-99/4A]] computer) was used in primary schools, emphasizing Logo's usefulness in teaching computing fundamentals to novice programmers.
* Sprite Logo, also developed by Logo Computer Systems Inc., had ten turtles that could run as independent processes. It ran on Apple II computers, with the aid of a Sprite Card inserted in one of the computer's slots.
* IBM marketed their own version of Logo (P/N 6024076), developed jointly by Logo Computer Systems, Inc. (LCSI), for their then-new IBM PC.
* [[ObjectLOGO]] is a variant of Logo with [[object-oriented programming]] extensions and lexical scoping. Version 2.7 was sold by Digitool, Inc.<ref>[http://www.digitool.com/ol-specs.html Object Logo] {{webarchive|url=https://web.archive.org/web/20080430083030/http://www.digitool.com/ol-specs.html |date=2008-04-30 }} page on the Digitool website (accessed 4 March 2008)</ref>  It is no longer being developed or supported, and does not run on versions of the Mac operating system later than 7.5.<ref>[http://www.digitool.com/ol-purchase.html Object Logo ordering page] on the Digitool website (accessed 4 March 2008)</ref>
* Dr. Logo was developed by [[Digital Research]] and distributed with computers including the [[IBM PCjr]],<ref name="DRI_1984_MicroNotes2"/> Atari ST and the [[Amstrad CPC]].<ref>{{Cite web|url=https://www.computerhistory.org/collections/search/|title=Catalog Search &#124; Computer History Museum|website=www.computerhistory.org}}</ref><ref>{{Cite web|url=https://www.computinghistory.org.uk/det/2666/Amstrad-CPC-6128/|title=Amstrad CPC 6128 - Computer - Computing History|website=www.computinghistory.org.uk}}</ref><ref>{{Cite web|url=https://www.habisoft.com/pcwwiki/doku.php?id=es:manual_del_amstrad_pcw_8256_8512_ingl%C3%A9s|title=es:manual_del_amstrad_pcw_8256_8512_ingles [PcwWiki]|website=www.habisoft.com}}</ref>{{anchor|DrLogo}}<!--The page Dr. Logo redirects here-->
* [[Acornsoft Logo]] was released in 1985. It is a commercial implementation of Logo for the 8-bit [[BBC Micro]] and [[Acorn Electron]] computers.<ref name="field">{{cite book | title=LOGO on the BBC computer and Acorn Electron | publisher=[[Macmillan Publishers|Macmillan]] | author=Field, Graham | year=1985 | isbn=0-333-39566-2}}</ref> It was developed for [[Acorn Computers]] as a full implementation of Logo. It features multiple screen [[turtle (robot)|turtle]]s and four-channel sound. It was provided on two 16kB [[Read-only memory|ROMs]], with utilities and [[device driver|driver]]s as accompanying software.<ref name="tmu four logos">{{cite news | url=http://www.nostalgia8.nl/logo/docs/mudeel1.jpg | title=Four Logos for the BBC Micro | publisher=[[The Micro User]] | work=The Micro User Education Special | access-date=February 20, 2012 | author=Radburn, Derek}}</ref>
*Lego Logo is a version of Logo that can manipulate robotic [[Lego]] bricks attached to a computer.<ref>{{cite journal|journal=[[Communications of the ACM]]|volume=36|number=7|date=July 1993|first=Mitchel|last=Resnick|title=Behavior Construction Kits|pages=64–71|doi=10.1145/159544.159593|s2cid=9263998|url=https://web.media.mit.edu/~mres/papers/BCK/BCK.html|accessdate=5 January 2022|doi-access=free}}</ref> It was implemented on the [[Apple II]] and used in American and other grade schools in the late 1980s and early 1990s.<ref>{{cite web|url=http://www.ucls.uchicago.edu/students/projects/1994-95/Lego-Logo/ProjectDescription.html|archiveurl=https://web.archive.org/web/20110720072907/http://www.ucls.uchicago.edu/students/projects/1994-95/Lego-Logo/ProjectDescription.html |archivedate=20 July 2011|title=The Laboratory Schools LEGO-LOGO Project|website=[[University of Chicago Laboratory Schools]]}}</ref> Lego Logo is a precursor to [[Scratch (programming language)|Scratch]].<ref>{{citation|last1=Bull|first1=G.|last2=Garofalo|first2=J.|last3=Hguyen|first3=N.|year=2020|title=Thinking about computational thinking: Origins of computational thinking in educational computing|journal=Journal of Digital Learning in Teacher Education|volume=36|number=1|pages=6–18|doi=10.1080/21532974.2019.1694381|s2cid=214563715}}</ref>

; First released in 1990s:
* In February 1990, ''Electron User'' published Timothy Grantham's simple implementation of Logo for the [[Acorn Electron]] under the article "Talking Turtle".<ref>{{cite web|url=http://www.acornelectron.co.uk/mags/eu/ills/7_05/s-p20.jpg|title=Talking Turtle|date=February 1990|pages=20–21|archiveurl=https://web.archive.org/web/20170328011620/http://www.acornelectron.co.uk/mags/eu/ills/7_05/s-p20.jpg |archivedate=28 March 2017}}</ref>
* Comenius Logo is an implementation of Logo developed by [[Comenius University Faculty of Mathematics, Physics and Informatics|Comenius University Faculty of Mathematics and Physics]]. It started development in December 1991, and is also known in other countries as SuperLogo, MultiLogo and MegaLogo.<ref>{{Cite web |date=2002-12-09 |title=History of Comenius Logo |url=http://www.input.sk/slogo/history.htm |access-date=2022-10-12 |archive-url=https://web.archive.org/web/20021209200055/http://www.input.sk/slogo/history.htm |archive-date=2002-12-09 }}</ref>
* [[UCBLogo]], also known as Berkeley Logo, is a free, cross-platform implementation of standard Logo last released in 2009. George Mills at MIT used UCBLogo as the basis for [[MSWLogo]] which is more refined and also free. Jim Muller wrote a book, ''The Great Logo Adventure'', which was a complete Logo manual and which used MSWLogo as the demonstration language.<ref>{{cite web|url=https://softronix.com/logo.html|accessdate=5 January 2022|title=MSWLogo, An Educational programming language|first=Jim|last=Muller|date=November 2001}}</ref> MSWLogo has evolved into [[FMSLogo]].

; First released from 2000 onwards:
* aUCBLogo is a rewrite and enhancement of [[UCBLogo]].
* Imagine Logo is a successor of Comenius Logo, implemented in 2000.<ref>{{Cite book |last=Andrej |first=Kalas |url=https://worldcat.org/oclc/854959806 |title=Imagine... a new generation of Logo : programmable pictures |last2=Blaho |first2=Ivan |year=2000 |oclc=854959806}}</ref> The English version was released by Logotron Ltd. in 2001.<ref>{{Cite web |date=2001-04-17 |title=Imagine {{!}} Press Release |url=http://logo.com/press_releases/imagine/index.html |access-date=2022-10-12 |archive-url=https://web.archive.org/web/20010417020957/http://logo.com/press_releases/imagine/index.html |archive-date=2001-04-17 }}</ref>
* [[LibreLogo]] is an extension to some versions of LibreOffice. Released in 2012, it is written in [[Python (programming language)|Python]]. It allows vector graphics to be written in Writer.
* Logo3D is a tridimensional version of Logo.
* POOL is a dialect of Logo with object-oriented extensions, implemented in 2014. POOL programs are compiled and run in the graphical IDE on [[Microsoft Windows]]. A simplified, cross-platform environment is available for systems supporting [[.NET Framework]].
* QLogo is an open-source and cross-platform rewrite of [[UCBLogo]] with nearly full UCB compatibility that uses hardware-accelerated graphics.
* Lynx is an online version of Logo developed by Logo Computer Systems Inc. It can run a large number of turtles, supports animation, parallel processes, colour and collision detection.
* LogoMor is an open-source online 3D Logo interpreter based on JavaScript and p5.js. It supports 3D drawings, animations, multimedia, 3D models and various tools. It also includes a fully-featured code editor based on [[CodeMirror]]
* LbyM is an open-source online Logo interpreter based on JavaScript, created and actively developed (as of 2021) for [[Sonoma State University]]'s ''Learning by Making'' program.<ref>{{cite web|url=https://make.sonoma.edu/learning-making|title=Learning by Making ¦ Make@SSU|date=14 August 2017|accessdate=8 January 2022}}</ref> It features traditional Logo programming, connectivity with a customized microcontroller and integration with a modern code editor.

== Influence ==

Logo was a primary influence on the [[Smalltalk]] programming language. It is also the main influence on the [[Etoys (programming language)|Etoys]] educational programming environment and language, which is essentially a Logo variant written in [[Squeak]] (itself a variant of Smalltalk). Logo influenced the procedure/method model in [[AgentSheets]] and [[AgentCubes]] to program agents similar to the notion of a turtle in Logo. Logo provided the underlying language for Boxer. Boxer was developed at [[University of California, Berkeley]] and MIT and is based on a ''literacy model'', making it easier to use for nontechnical people.<ref>{{Cite web |title=Boxer - EduTech Wiki |url=https://edutechwiki.unige.ch/en/Boxer |access-date=2024-04-10 |website=edutechwiki.unige.ch}}</ref>

KTurtle is a variation of Logo implemented at [[Qt (software)|Qt]] for the [[KDE]] environment loosely based on Logo.<ref>{{cite web |url=http://edu.kde.org/kturtle/ |title=The KDE Education Project – KTurtle |website=edu.kde.org |url-status=live |archive-url=https://web.archive.org/web/20060827165231/http://edu.kde.org/kturtle/ |archive-date=2006-08-27 }}</ref>

Two more results of Logo's influence are [[Kojo (programming language)|Kojo]], a variant of Scala, and [[Scratch (programming language)|Scratch]], a visual, drag-and-drop language which runs in a web browser.

==References==
{{Reflist|refs=
<ref name="DRI_1984_MicroNotes2">{{cite news |title=DRI ships 128K version of Dr. Logo |newspaper=[[Micro Notes (Digital Research)|Micro Notes]] - Technical information on Digital Research products |volume=2 |number=2 |date=May 1984 |publisher=[[Digital Research, Inc.]] |location=Pacific Grove, CA, USA |id=NWS-106-002 |page=4 |url=https://www.z80cpu.eu/mirrors/oldcomputers.dyndns.org/public/pub/manuals/DRI_Micronotes_Vol2_1,2,3_full.pdf |access-date=2020-02-11 |url-status=live |archive-url=https://web.archive.org/web/20200211005618/https://www.z80cpu.eu/mirrors/oldcomputers.dyndns.org/public/pub/manuals/DRI_Micronotes_Vol2_1,2,3_full.pdf |archive-date=2020-02-11 |quote=[…] [[Dr. Logo]] first appeared on the retail market in fall of 1983 for the [[IBM PC]] and climbed to the top of the [[Softsel Hot List]]. The retail release included [[SpeedStart CP/M]], an abridged version of [[CP/M-86|CP/M]] that boots automatically when the system is turned on. […]}} [https://web.archive.org/web/20200211102248/https://www.z80cpu.eu/mirrors/oldcomputers.dyndns.org/public/pub/manuals/DRI_Micronotes_Vol2_1,2,3_bw_full.pdf<!-- https://www.z80cpu.eu/mirrors/oldcomputers.dyndns.org/public/pub/manuals/DRI_Micronotes_Vol2_1,2,3_bw_full.pdf -->]</ref>
}}

==Further reading==
{{refbegin}}
* [https://history.dcs.ed.ac.uk/archive/docs/ArtificialIntelligence/art0084.html ''To Artificial Intelligence'' (1976)] Early AI textbook where Logo is used extensively. (Using the [[Edinburgh University]] dialect, AI2LOGO)
* [https://www.amazon.com/gp/product/0262510375 Turtle Geometry] Abelson and diSessa
* ''Children Designers'', Idit Harel Caperton, Ablex Publishing Corporation {{ISBN|0893917885}}. Available [https://www.amazon.com/Children-Designers-Interdisciplinary-Constructions-Computer-Rich/dp/0893917885/ online]
* ''Learning With Logo'', Daniel Watt, McGraw Hill, {{ISBN|0-07-068570-3}}. Available Through Amazon
* Teaching With Logo: Building Blocks For Learning, Molly Watt and Daniel Watt, Addison Wesley (now Pearson) 1986, {{ISBN|0-201-08112-1}} Available through Amazon
* {{cite magazine|magazine=Byte|year=1982|volume=7|issue=8|publisher=McGraw-Hill|title=Logo|url=https://ia600605.us.archive.org/14/items/byte-magazine-1982-08/1982_08_BYTE_07-08_Logo.pdf}} (''Byte'' magazine special 1982 issue featuring multiple Logo articles).
{{refend}}

==External links==
* {{commons category-inline}}
* {{Wikibooks inline|Logo Programming}}

{{Logo programming}}
{{Lisp programming language}}
{{Authority control}}

[[Category:1967 in robotics]]
[[Category:Apple II software]]
[[Category:Dynamically typed programming languages]]
[[Category:Domain-specific programming languages]]
[[Category:Educational programming languages]]
[[Category:Free educational software]]
[[Category:Functional languages]]
[[Category:Lisp programming language family]]
[[Category:Logo programming language family]]
[[Category:Programming languages]]
[[Category:Programming languages created in 1967]]
[[Category:Robot programming languages]]