Apertium is a free/open-source machine translation platform, initially aimed at related-language pairs but expanded to deal with more divergent language pairs (such as English-Catalan). 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.
Apertium welcomes new developers: if you think you can improve the engine or the tools, or develop linguistic data for us, do not hesitate to contact us.
Documentation can be found on our Wiki under the Documentation sub-page. We have published various conference papers and journal articles, a list of which may be found on the Wiki under Publications.
Current versions of the Apertium toolbox as well as of language-pair data are available from the SourceForge page. Installation instructions for Apertium on all major platforms are provided on the Wiki's Installation page.
The quickest way to contact us is by joining our IRC channel, #apertium at irc.freenode.net, where users and developers of Apertium meet. You don't need an IRC client; you can use freenode webchat.
Also, subscribe to the apertium-stuff mailing list, where you can post longer proposals or issues, as well as follow general Apertium discussions.
Feel free to contact us via the apertium-contact mailing list if you find a mistake, there's a project you would like to see us work on, or you would like to help out.