5 open-source Translation & Localisation vendors.

Open-source software for Translation & Localisation that you can self-host, with auditable source code — regardless of the developer's headquarters.

• ApertiumSelf-hosted / open source

  Open-source rule-based machine translation platform (GNU GPL) originating from the Spanish government-funded OpenTrad project, developed by the Transducens research group at Universitat d'Alacant; specialized in under-resourced and minoritized languages, actively maintained (v3.9.12, April 2025) with over 100 language pairs as of 2026.

  Spain

• MateCatEU sovereign

  Open-source enterprise CAT tool for professional translators developed by Translated srl

  Italy

• ModernMTEU sovereign

  Adaptive neural machine translation engine that learns from translator corrections

  Italy

• TolgeeSelf-hosted / open source

  Czech open-source (Apache 2.0) developer-friendly localisation platform.

  Czechia

• WeblateEU sovereign

  Open-source web-based continuous localization platform for developers

  Czechia