5 open-source Writing Assistance & Grammar vendors
Open-source software for Writing Assistance & Grammar that you can self-host, with auditable source code — regardless of the developer's headquarters.
- vendors scored
- 5
- European
- 5
- foreign-owned
- 1
- last checked
- 10 October 2026
Vendors, scored
Score per vendor: 0 = high exposure, 100 = sovereign
Sort
- Sovereignty score 94 out of 100GrammalecteFrance · Self-hosted / open sourceOpen-source French grammar and typography checker running locally in LibreOffice, Firefox, Thunderbird and other editors; developed in France.
- Sovereignty score 94 out of 100KateGermany · Self-hosted / open sourceFast open-source multi-document text editor from KDE, developed by the KDE community; the non-profit KDE e.V. is based in Berlin.
- Sovereignty score 94 out of 100LanguageToolGermany · EU-hosted, non-EU parent · owner in United StatesGerman open-source grammar, spelling, and style checker supporting 30+ languages
- Sovereignty score 94 out of 100Notepad++France · Self-hosted / open sourceFree open-source text and source code editor for Windows with syntax highlighting and plugins.
- Sovereignty score 92 out of 100CKEditorPoland · Self-hosted / open sourceRich text editor developed by CKSource (legally headquartered in Warsaw, Poland, ul. Okopowa 58/72), distributed under a dual GPL/commercial licence. Actively sold in 2026 with integrated AI features (AI Chat, AI Review, AI Translate, AI Quick Actions) that keep human review control over AI-generated edits.
Assess your own stack in the assessment
Assess your stack →