LanguageTool
{{short description|Free and open-source spell and grammar checker}}
{{Infobox software
| name = LanguageTool
| title = LanguageTool
| logo = LanguageTool Logo (2018).svg
| screenshot = LanguageTool WikiCheck.png
| caption = LanguageTool WikiCheck
| developer = Daniel Naber and Marcin Miłkowski
| released = {{Start date and age|2005|08|15|df=yes}}
| latest release version = {{wikidata|property|edit|reference|P348}}
| latest release date = {{wikidata|qualifier|P348|P577}}
| programming language = Java
| platform = Java SE
| language count =
| language footnote =
| size = {{ubl
|Desktop app: 156 MB{{Cite web|url=https://languagetool.org/download/|title=Index of /download/|website=languagetool.org}}
|n-gram data: 8.34 GB{{Cite web|url=https://languagetool.org/download/ngram-data/|title=Index of /download/ngram-data/|website=languagetool.org}}
}}
| language =
| genre = Grammar checker
| license = GNU LGPL v2.1+
}}
LanguageTool is a free and open-source grammar, style, and spell checker, and all its features are available for download.{{Cite web|url=https://languagetool.org/#libreoffice|title=LanguageTool - Spell and Grammar Checker|website=LanguageTool}}{{Cite web |last=Ashwin |date=2019-07-08 |title=LanguageTool is a free, open-source, grammar and spell checker - gHacks Tech News |url=https://www.ghacks.net/2019/07/08/languagetool-is-a-free-open-source-grammar-and-spell-checker/ |access-date=2025-04-23 |website=gHacks Technology News |language=en-US}} The LanguageTool website connects to a proprietary sister project called LanguageTool Premium (formerly LanguageTool Plus), which provides improved error detection for English and German, as well as easier revision of longer texts, following the open-core model.
Overview
LanguageTool was started by Daniel Naber for his diploma thesis{{cite web|url=http://danielnaber.de/languagetool/download/style_and_grammar_checker.pdf|title=A Rule-Based Style and Grammar Checker|author=Daniel Naber|website=Daniel Naber.de|access-date=30 June 2018}} in 2003 (then written in Python). It now supports 31 languages, each developed by volunteer maintainers, usually native speakers of each language.{{cite web|title=Supported languages|url=https://languagetool.org/languages/|date=28 December 2016|access-date=29 December 2016}} Based on error detection patterns, rules are created and then tested for a given text.
The core app itself is free and open-source and can be downloaded for offline use. Some languages use 'n-gram' data,{{cite web|url=https://languagetool.org/download/ngram-data/ |title=N-Gram Data Download Page |website=languagetool.org |date=2019-03-30 |access-date=2019-03-30}} which is massive and requires considerable processing power and I/O speed, for some extra detections. As such, LanguageTool is also offered as a web service that does the processing of 'n-grams' data on the server-side. LanguageTool "Premium" also uses n-grams as part of its freemium business model.
LanguageTool web service can be used via a web interface in a web browser, or via a specialized client-side plug-ins for Microsoft Office, LibreOffice, TeXstudio, Apache OpenOffice, Vim, Emacs, Firefox, Thunderbird, and Google Chrome.
LanguageTool does not check a sentence for grammatical correctness, but whether it contains typical errors. Therefore, it is easy to invent ungrammatical sentences that LanguageTool will still accept. Error detection succeeds with a variety of rules based on XML or written in Java.{{Citation|title=Linux Administration|url=http://dx.doi.org/10.1007/978-1-4302-0214-1_15|work=Pro Oracle Database 10g RAC on Linux|year=2006 |pages=385–400|place=Berkeley, CA|publisher=Apress|doi=10.1007/978-1-4302-0214-1_15 |isbn=978-1-59059-524-4|access-date=2022-02-23 |url-access=subscription}} XML-based rules can be created using an online form.{{Cite web |title=Create a new LanguageTool rule |url=https://community.languagetool.org/ruleEditor2/ |access-date=2023-10-26 |website=community.languagetool.org}}
More recent developments rely on large n-gram libraries that offer suggestions for improving misspellings with the help of artificial neural networks.{{Cite book|url=https://www.worldcat.org/oclc/1066024545|title=SKILL 2018 : Fachwissenschaftlicher Informatik-Kongress, Studierendenkonferenz Informatik, 26.-27. September 2018, Berlin|date=2018|others=Gesellschaft für Informatik|isbn=978-3-88579-448-6|location=[Bonn]|oclc=1066024545}}
In April 2023 Learneo acquired LanguageTool.{{Cite web |last=Naber |first=Daniel |title=LanguageTool joins Learneo |url=https://forum.languagetool.org/t/languagetool-joins-learneo/8865}}{{Cite web |title=Learneo {{!}} Updates {{!}} Learneo, Inc. Accelerates AI Writing Innovation with LanguageTool Acquisition |url=https://www.learneo.com/news/learneo-inc-accelerates-ai-writing-innovation-with-languagetool-acquisition |access-date=2025-04-10 |website=www.learneo.com |language=en}}{{Cite web |last=Pathak |first=Shalini |date=2023-04-10 |title=US-Based Learneo Acquires Multilingual Writing Assistant LanguageTool – EdTechReview |url=https://www.edtechreview.in/news/us-based-learneo-acquires-multilingual-writing-assistant-languagetool/ |access-date=2025-04-23 |language=en-US}}{{Cite web |last=Alston |first=Fiona |date=2023-04-05 |title=Learneo adds LanguageTool to its stable of AI-powered writing tools and services, in its latest acquisition |url=https://tech.eu/2023/04/05/learneo-adds-languagetool-to-its-stable-of-ai-powered-writing-tools-and-services-in-its-latest-acquisition/ |access-date=2025-04-23 |website=Tech.eu |language=en-GB}}
See also
{{Portal|Free and open-source software}}
References
{{Reflist|2}}
External links
- {{official website|https://languagetool.org}}
{{Website-stub}}
Category:Cross-platform free software
Category:Software using the GNU Lesser General Public License
Category:Nonfree Firefox WebExtensions
Category:Free software programmed in Java (programming language)