View source for Comparison of Prolog implementations

{{short description|None}}
[[File:Early Prolog timeline.svg|thumb|upright=2|Timeline of some early Prolog systems, up to the ISO Standard]]
The following '''Comparison of Prolog implementations''' provides a reference for the relative feature sets and performance of different implementations of the [[Prolog]] computer [[programming language]].  A comprehensive discussion of the most significant [[Prolog]] systems is presented in an article published in the 50-years of Prolog anniversary issue of the journal ''Theory and Practice of Logic Programming'' (TPLP).<ref name=prolog50>{{citation |author=Philipp Körner |author2=Michael Leuschel |author3=João Barbosa |author4=Vítor Santos Costa |author5=Verónica Dahl |author6=Manuel V. Hermenegildo |author7=Jose F. Morales |author8=Jan Wielemaker |author9=Daniel Diaz |author10=Salvador Abreu |author11=Giovanni Ciatto |title=Fifty Years of Prolog and Beyond |date=November 2022 |journal=Theory and Practice of Logic Programming|volume=22|issue=6 |pages=776–858 |doi=10.1017/S1471068422000102 |doi-access=free|hdl=10174/33387 |hdl-access=free }}</ref>

==Portability==
[[File:Prolog systems.svg|thumb|upright=2|Prolog Heritage.<br />Systems with a dark gray background are not supported any more. Arrows denote influences and inspiration of systems. Quick legend: JIT = "Just in Time Compiler", JVM = "Java Virtual Machine", TOAM = "Tree-Oriented Abstract Machine"]]
There are Prolog [[Programming language implementation|implementations]] that are radically different, with different syntax and different semantics (e.g. Visual Prolog)<ref name=portability2011>{{Cite book | last1 = Wielemaker | first1 = J. | last2 = Costa | first2 = V. T. S. | chapter = On the Portability of Prolog Applications | doi = 10.1007/978-3-642-18378-2_8 | title = Practical Aspects of Declarative Languages | series = Lecture Notes in Computer Science | volume = 6539 | pages = 69–83 | year = 2011 | isbn = 978-3-642-18377-5 | citeseerx = 10.1.1.1030.9396 }}</ref> and sub-communities have developed around different implementations.<ref name=portability2011/>

Code that strictly conforms to the ISO-Prolog core language is portable across ISO-compliant implementations. However, the ISO standard for modules is an extension which was not fully adopted in most Prolog systems.<ref name=portability2011/><ref name=prolog50/>

Factors that can adversely affect portability include:  use of bounded vs. unbounded integer arithmetic, additional types such as string objects, advanced numeric types (rationals, complex), feature extensions such as [[Unicode]], threads, and tabling.<ref>Jan Wielemaker and Vıtor Santos Costa: [http://www.swi-prolog.org/download/publications/porting.pdf Portability of Prolog programs: theory and case-studies]. [http://www.floc-conference.org/CICLOPS-WLPE-accepted.html CICLOPS-WLPE Workshop 2010] {{Webarchive|url=https://web.archive.org/web/20100716184811/http://www.floc-conference.org/CICLOPS-WLPE-accepted.html |date=2010-07-16 }}.</ref>  Use of libraries unavailable in other implementations and library organisation:<ref name=portability2011/> 
<blockquote>Currently, the way predicates are spread over the libraries and system built-ins differs enormously. [...] Fortunately, there are only few cases where we find predicates with the same name but different semantics (e.g. <code>delete/3</code>)</blockquote>

==Main features==
{| class="wikitable sortable"
|-
! colspan="3" | Platform
! colspan="8" | Features
! colspan="3" | Toolkit
!| Prolog Mechanics
|-
! style="background:#ffdead;" | Name
! style="background:#ffdead;" | OS
! style="background:#ffdead;" | Licence
! {{verth|cellstyle=background:#ffdead;|Native Graphics}}
! {{verth|cellstyle=background:#ffdead;|Compiled Code}}
! {{verth|cellstyle=background:#ffdead;|Unicode}}
! {{verth|cellstyle=background:#ffdead;|Object Oriented}}
! {{verth|cellstyle=background:#ffdead;|Native OS Control}}
! {{verth|cellstyle=background:#ffdead;|Stand Alone Executable}}
! {{verth|cellstyle=background:#ffdead;|C Interface{{efn|name="C"|C/Java interface can also be used for graphics and OS control.}}}}
! {{verth|cellstyle=background:#ffdead;|Java Interface{{efn|name="C"}}}}
! {{verth|cellstyle=background:#ffdead;|Interactive Interpreter}}
! {{verth|cellstyle=background:#ffdead;|Debugger}}
! {{verth|cellstyle=background:#ffdead;|Code Profiler}}
! style="background:#ffdead;" | Syntax
|-
|AllegroProlog<ref>[https://franz.com/products/allegro-common-lisp/acl_prolog.lhtml Allegro Prolog]</ref>
|[[Unix]], [[Microsoft Windows|Windows]], [[Mac OS X]]
|{{proprietary}} (limited free edition available)
|
|{{Yes}}
|{{Yes}}
|{{Yes}}
|{{Yes}}, via Lisp
|{{Yes}}
|{{Yes}}, via Lisp
|{{Yes}}, via Lisp
|{{Yes}}
|{{Yes}}
|{{Yes}}, via Lisp
|S-expressions. Full Common Lisp integration.
|-
|{{rh}}|[[BProlog]]
|[[Unix]], [[Microsoft Windows|Windows]], [[Mac OS X]]
|{{proprietary}} (free for non-commercial uses)
|
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|ISO-Prolog, plus event-handling, CLP(FD), and tabling
|-
|{{rh}}|[[Ciao (programming language)|Ciao]]
|[[Unix]], [[Microsoft Windows|Windows]], [[Mac OS X]]
|{{open source|[[GPL]], [[GNU Lesser General Public License|LGPL]]}}
|
|{{yes}}
|
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|ISO-Prolog, plus extensions
|-
|{{rh}}|DOS-Prolog<ref>{{Cite web |date=5 November 2023 |title=DOS-Prolog 8.0 |url=https://www.lpa.co.uk/dos.htm |website=Logic Programming Associates}}</ref>
|[[MS-DOS]]
|{{proprietary}}
|{{yes}}
|{{yes}}
|{{yes}}
|
|{{yes}}
|{{yes}}
|
|
|
|{{yes}}
|
|Edinburgh Prolog
|-
|{{rh}}|[[ECLiPSe]]
|[[Linux]], [[Microsoft Windows|Windows]], [[Solaris (operating system)|Solaris]], [[macOS]]
|{{open source|[[Mozilla Public License|MPL]]}}
|
|{{yes}}
|
|
|{{yes}}
|
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|Extended Prolog, Multi-dialect, including ISO
|-
|{{rh}}|[[GNU Prolog]]
|[[Unix]], [[Microsoft Windows|Windows]], [[Mac OS X]]
|{{open source|[[GNU General Public License|GPL]], [[LGPL]]}}
|
|{{yes}}
|
|
|{{yes}}
|{{yes}}
|{{yes}}
|
|{{yes}}
|{{yes}}
|
|ISO-Prolog
|-
|-
|{{rh}}|[[JIProlog]]<ref>[http://www.jiprolog.com JIProlog]</ref>
|[[JVM]], [[Android (operating system)|Android]]
|{{open source|[[GNU Affero General Public License|AGPL]] (commercial support available)}}
|{{yes}}
|
|{{yes}}
|
|{{yes}} via Java
|{{yes}}
|{{yes}} via Java
|{{yes}}
|{{yes}}
|{{yes}}
|
|ISO-Prolog
|-
|{{rh}}|JLog<ref name="JLog Homepage">{{Cite web |title=JLog Homepage |url=https://jlogic.sourceforge.net/ |access-date=2023-11-03 |website=jlogic.sourceforge.net}}</ref>
|[[JVM]]
|{{open source|[[GNU General Public License|GPL]]}}
|{{yes}}
|{{yes}}
|
|
|
|
|
|{{yes}}
|{{yes}}
|
|
|ISO-Prolog
|-
|{{rh}}|JScriptLog<ref name="JLog Homepage"/>
|Web Browser
|{{open source|[[GNU General Public License|GPL]]}}
|
|
|
|
|
|
|
|
|{{yes}}
|
|
|ISO-Prolog
|-
|{{rh}}|jTrolog<ref>{{Cite web |date=2012-11-13 |title=Jtrolog — Java.net |url=http://java.net/projects/jTrolog |access-date=2023-11-03 |archive-url=https://web.archive.org/web/20121113023104/http://java.net/projects/jTrolog |archive-date=2012-11-13 }}</ref>
|[[JVM]]
|{{open source|[[GNU Lesser General Public License|LGPL]]}}
|
|
|{{yes}}
|
|
|
|
|{{yes}}
|{{yes}}
|{{yes}}
|
|ISO-Prolog
|-
|{{rh}}|WIN-Prolog<ref>{{Cite web |date=5 November 2023 |title=WIN-Prolog 8.0 |url=https://www.lpa.co.uk/win.htm |website=Logic Programming Associates}}</ref>
|[[Microsoft Windows|Windows]]
|{{proprietary}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|Edinburgh Prolog with extensions
|-
|{{rh}}|Open Prolog<ref>[https://web.archive.org/web/20050203201646/http://www.cs.tcd.ie/open-prolog/ Open Prolog Home Page]</ref>
|Mac OS [[System 7]]
|{{proprietary|[[Freeware]]}}
|
|
|
|
|
|
|
|
|
|{{yes}}
|
|
|-
|{{rh}}|[[Poplog]] Prolog
|[[Linux]] (32- and 64-bit), [[Unix]], [[Microsoft Windows|Windows]] 
|{{open source|Free Open Source}}
|Only through [[POP-11]], on Linux
|{{yes}}
|
|
|{{yes}}
|{{yes}}
|{{yes}}
|
|{{yes}}
|{{yes}}
|
|Edinburgh Prolog, with interfaces to Poplog Common Lisp and Pop-11
|-
|{{rh}}|[[Scryer Prolog]]<ref>[https://www.scryer.pl Scryer Prolog]</ref>
|[[Linux]], [[Microsoft Windows|Windows]], [[macOS]]
|{{open source|[[BSD License]]}}
|
|
|{{yes}}
|
|
|
|
|
|{{yes}}
|
|
|ISO-Prolog
|-
| {{rh}} class="table-rh" |[[SICStus Prolog]]
|[[Unix]], [[Linux]], [[Microsoft Windows|Windows]], [[macOS]]
|{{proprietary}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|[[Comparison of Prolog standards compliance|ISO-Prolog]]
|-
|{{rh}}|[[Strawberry Prolog]]<ref>[https://dobrev.com Strawberry Prolog]</ref>
|[[Unix]], [[Microsoft Windows|Windows]]
|{{proprietary|[[Freeware]]}}
|{{yes}}
|{{yes}}
|{{yes}}
|
|
|{{yes}}
|
|
|
|{{yes}}
|
|Not ISO-Prolog + extensions
|-
|{{rh}}|[[SWI-Prolog]]
|[[Unix]], [[Linux]], [[Microsoft Windows|Windows]], [[macOS]]
|{{open source|[[BSD License]]}}
|{{yes}}
|{{yes}}
|{{yes}}
|
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|ISO-Prolog, Edinburgh Prolog
|-
|{{rh}}|[[tuProlog]]<ref>[http://tuprolog.unibo.it tuProlog]</ref>
|[[JVM]], [[Android (operating system)|Android]]
|{{open source|[[GNU Lesser General Public License|LGPL]]|}}
|{{yes}}
|
|{{yes}}
|
|
|
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|
|ISO-Prolog
|-
|{{rh}}|[[Visual Prolog]]
|[[Microsoft Windows|Windows]]
|{{proprietary|[[Freeware]]}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|
|
|{{yes}}
|{{yes}}
|
|-
|{{rh}}|[[XSB|XSB Prolog]]
|[[Linux]], [[Microsoft Windows|Windows]], [[Solaris (operating system)|Solaris]], [[macOS]]
|{{open source|[[GNU Lesser General Public License|LGPL]]}}
|
|{{yes}}
|{{yes}}
|
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|ISO-Prolog, tabled WFS
|-
|{{rh}}|[[YAP-Prolog]]
|[[Linux]], [[Microsoft Windows|Windows]], [[Solaris (operating system)|Solaris]], [[Mac OS X]], [[HP-UX]]
|{{open source|[[GNU General Public License|GPL]] or Artistic (user choice)}}
|
|{{yes}}
|{{yes}}
|
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|{{yes}}
|
|ISO-Prolog, Edinburgh Prolog, Quintus and SICStus Prolog compatible
|}

==Operating system and web-related features==
{| class="wikitable"
|-
|
! colspan="4" | OS-related
! colspan="4" | Web-related
|-
! style="background:#ffdead;" | Name
! style="background:#ffdead;" | Conditional compilation
! style="background:#ffdead;" | Sockets
! style="background:#ffdead;" | Multi-threading
! style="background:#ffdead;" | Tabling
! style="background:#ffdead;" | HTTP client
! style="background:#ffdead;" | HTTP server
! style="background:#ffdead;" | HTML Parser
! style="background:#ffdead;" | RDF Triple store
|-
|{{rh}}|[[BProlog]]
|
|
|
| {{yes}}
|
|
|
|
|-
|{{rh}}|[[Ciao (programming language)|Ciao]]
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
|
|-
|{{rh}}|[[ECLiPSe]]
| {{Yes}}
| {{Yes}}
| {{Yes}}
|
| {{Yes}}
|
| {{Yes}}
|
|-
|{{rh}}|[[GNU Prolog]]
| 
| {{Yes}}
|
|
|
|
|
|
|-
|{{rh}}|[[WIN-Prolog]]
|
| {{yes}}
| 
| 
| {{yes}}
| {{yes}}
| {{yes}}
| 
|-
|{{rh}}|[[Scryer Prolog]]
|
| {{yes}}
|
| {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
|
|-
|{{rh}}|[[SICStus Prolog]]
| {{yes}}
| {{Yes}}
| {{Yes}}
|
|
|
|
|
|-
|{{rh}}|[[SWI-Prolog]]
| {{yes}}
| {{yes}}
| {{yes}}
|  {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
|-
|{{rh}}|[[Visual Prolog]]
| {{yes}}
| {{yes}}
| {{yes}}
| 
| {{yes}}
| {{yes}}
| {{yes}}
|
|-
|{{rh}}|[[XSB]]
| {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
|
|
|
|-
|{{rh}}|[[YAP-Prolog]]
| {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
|
|
|
|
|}

==Static analysis==
{| class="wikitable"
|-
! style="background:#ffdead;" | Name
! style="background:#ffdead;" | Type checker
! style="background:#ffdead;" | Determinacy checker
! style="background:#ffdead;" | Call-pattern checker
|-
|{{rh}}|[[Ciao (programming language)|Ciao]]
| {{yes}}
| {{yes}}
| {{yes}}
|-
|{{rh}}|[[GNU Prolog]]
|
|
|
|-
|{{rh}}|[[SICStus Prolog]]
|
| {{yes}}
|
|-
|{{rh}}|[[SWI-Prolog]]
|
| {{yes}}
|
|-
|{{rh}}|[[Visual Prolog]]
| {{yes}}
| {{yes}}
| {{yes}}
|-
|{{rh}}|[[XSB]]
|
|
|
|-
|{{rh}}|[[YAP-Prolog]]
|
|
|
|}

==Optimizations==
{| class="wikitable"
|-
! style="background:#ffdead;" | Name
! style="background:#ffdead;" | [[Tail-call optimization|Tail-Call Optimization]]
! style="background:#ffdead;" | Choice Point Elimination
! style="background:#ffdead;" | Environment Trimming
! style="background:#ffdead;" | [[Term indexing|Just-in-Time Indexing]]
|-
|{{rh}}|[[Ciao (programming language)|Ciao]]
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
| {{dunno}}
|-
|{{rh}}|[[ECLiPSe]]
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
| {{n/a|multi-argument (compile time)}} 
|-
|{{rh}}|[[GNU Prolog]]
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
| 
|-
|{{rh}}|[[SICStus Prolog]]
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
| 
|-
|{{rh}}|[[SWI-Prolog]]
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
|-
|{{rh}}|[[Visual Prolog]]
| {{yes|Yes (compile time)}}
| {{yes|Yes (compile time)}}
| {{n/a|N/A}}
| {{n/a|N/A (compile time)}} 
|-
|{{rh}}|[[XSB]]
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
| {{dunno}}
|-
|{{rh}}|[[YAP-Prolog]]
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
| {{yes|Yes}}
|}

== Release ==
{| class="wikitable sortable"
|-
! style="background:#ffdead;" | Name
! style="background:#ffdead;" | Version
! style="background:#ffdead;" | Date
|-
| {{rh}} class="table-rh" | AllegroProlog
|1.1.2
|2018-12-12
|-
| {{rh}} class="table-rh" |[[BProlog]]
|8.1
|2014-02-23
|-
| {{rh}} class="table-rh" |[[JIProlog]]
|4.1.7.1
|2021-08-26
|-
| {{rh}} class="table-rh" |[[Ciao (programming language)|Ciao]]
|1.22
|2022-09-28
|-
| {{rh}} class="table-rh" |DOS-Prolog
|8.0
|
|-
| {{rh}} class="table-rh" |[[ECLiPSe]]
|7.1
|2023-01-01
|-
| {{rh}} class="table-rh" |[[GNU Prolog]]
|1.5.0
|2023-02-21
|-
| {{rh}} class="table-rh" |[http://jlogic.sourceforge.net/ JLog]
|1.3.6
|2007-09-13
|-
| {{rh}} class="table-rh" |[http://jlogic.sourceforge.net/ JScriptLog]
|0.7.5 beta
|2007-09-10
|-
| {{rh}} class="table-rh" |[https://web.archive.org/web/20121113023104/http://java.net/projects/jTrolog jTrolog]
|
|
|-
| {{rh}} class="table-rh" |WIN-Prolog
|8.0
|2022-07-14
|-
| {{rh}} class="table-rh" |Open Prolog
|
|
|-
| {{rh}} class="table-rh" |[[Poplog]] Prolog
|V16
|2020-01-06
|-
| {{rh}} class="table-rh" |[[Scryer Prolog]]
|0.9.3
|2023-11-02
|-
| {{rh}} class="table-rh" |[[SICStus Prolog]]
|4.9.0
|2023-12-18
|-
| {{rh}} class="table-rh" |[[Strawberry Prolog]]
|6.1 
|2023-08-23
|-
| {{rh}} class="table-rh" |[[SWI-Prolog]]
|9.1.18
|2023-11-01
|-
| {{rh}} class="table-rh" |[[tuProlog]]
|2P-Kt 0.31.18
|2023-10-24
|-
| {{rh}} class="table-rh" |[[Visual Prolog]]
|10, Build 1000
|2021-04-15
|-
| {{rh}} class="table-rh" |[[XSB]] Prolog
|5.0
|2022-05-15
|-
| {{rh}} class="table-rh" |[[YAP (Prolog)|YAProlog]]
|7.1.0
|2020-12-19
|}

==Benchmarks==
* Benchmarking issues: [http://www.cs.kuleuven.be/publicaties/rapporten/cw/CW312.abs.html Odd Prolog benchmarking], Performance differences.<ref>B. Demoen, and P. Nguyen, About unnecessary performance differences between Prolog implementations, Proceedings of the Colloquium on Implementation of Constraint and Logic Programming Systems (CICLOPS 2001)</ref>
* Benchmarking software: [https://www.cs.cmu.edu/afs/cs/project/ai-repository/ai/lang/prolog/code/library/0.html older], [http://www.cs.cmu.edu/afs/cs/project/ai-repository/ai/lang/prolog/code/bench/dobry.txt Dobry's Benchmarks]<!-- {{dead link|date=August 2017 |bot=InternetArchiveBot |fix-attempted=yes }} -->, [http://portal.acm.org/citation.cfm?id=893977 Aquarius benchmark suite], (Bothe, 1990),<ref>{{Cite journal| year = 1990| doi = 10.1145/122193.122197| pages = 54–60| volume = 25| journal = ACM SIGPLAN Notices| title = A prolog space benchmark suite| last1 = Bothe | first1 = K.| issue = 12| doi-access = free}}</ref> [http://www.cs.kuleuven.be/~bmd/hProlog/iclpgcbenches.tar.gz (Demoen et al. 2001)], [http://www.cs.unipr.it/China/Benchmarks/descriptions benchmark descriptions]
* Benchmarking results: [https://web.archive.org/web/20100227050426/http://www.probp.com/performance.htm B-Prolog], [https://web.archive.org/web/20080203174047/http://www.sics.se/isl/sicstuswww/site/performance.html SICStus], XSB,<ref>[http://citeseer.ist.psu.edu/swift93summary.html A Summary of XSB Performance (1993)]</ref> SICStus vs Yap vs {{proper name|hProlog}}<ref>{{Cite book| volume = 2401| pages = 194–208| year = 2002| doi = 10.1007/3-540-45619-8_14| chapter = Copying Garbage Collection for the WAM: to Mark or Not to Mark? | first3 = R. | first1 = B.| title = Logic Programming| last2 = Nguyen | first2 = P. L.| last3 = Vandeginste| last1 = Demoen| series = Lecture Notes in Computer Science| isbn = 978-3-540-43930-1| citeseerx = 10.1.1.13.2586}}</ref>
* Benchmarking results: [https://web.archive.org/web/20110719062358/http://www.michaels-website.de/2010/08/prolog-in-the-jvm-survey-of-prolog-engines-written-in-java/ Survey of java prolog engines] by Michael Zeising
* Benchmarking results: [https://www3.cs.stonybrook.edu/~pfodor/openrulebench_web/ OpenRuleBench yearly open-source benchmark of rule engines]

==Notes==
{{notelist}}

== References ==

{{reflist}}

==External links==
* [http://www.complang.tuwien.ac.at/ulrich/prolog_misc/systems.html Overview of Prolog Systems] by Ulrich Neumerkel
* [http://www.complang.tuwien.ac.at/ulrich/iso-prolog/conformity_assessment Conformity assessment I: Syntax]

[[Category:Prolog programming language family]]
[[Category:Software comparisons]]