Apertium is a free/open-source project for machine translation and natural language processing.

The Apertium project develops a free/open-source platform for machine translation and language technology. We try to focus our efforts on lesser-resourced and marginalised languages, but also work with more widely-spoken languages. The platform provides,

a language-independent machine translation engine

tools to manage the linguistic data necessary to build a machine translation system for a given language pair and

linguistic data for a growing number of language pairs.

It is being developed around the world, in universities and companies and by independent free-software developers. There are currently 42 published language pairs within the project (including a number of "firsts" — for example Aragonese—Spanish, Crimean Tatar—Turkish, Spanish—Occitan, Breton—French, Italian—Sardinian among others), and several more in development.

Primary Open Source License: GNU General Public License version 3.0 (GPL-3.0)

Programming Languages:

  • c++
  • python
  • js
  • html
  • bash


  • machine translation
  • machine learning
  • finite-state machines
  • annotation
  • natural language processing