I have reviewed the web GNU software, and really have not found a site that has several translations. However, if I have found references to how to translate, as in the
following directions (in the footer).
https://www.gnu.org/software/anubis/
https://www.gnu.org/software/acm/
https://www.gnu.org/software/alive/
These web reference that can be translated, and have presented a menu where different languages.
One of the directions that have a Spanish translation is ocrad web.
https://www.gnu.org/software/ocrad/ocrad.html
This site has a translation. Reading the documentation for the translation of articles, web pages use the same software system, using po file templates. However, I could not download the template po PSPP website (maybe you have it to generate).
https://www.gnu.org/server/standards/translations/po-how-to.html
Follow the instructions on the above website to try.
Anyway, I sent an email to the list of the translation team, but still expect an answer.
For now, I created an account
on Github where I will keep my contributions to PSPP.
Regarding the translation of documents and web I have it in plain text, until you have more knowledge to the proper method.
https://github.com/bedf/PSPP-document-translations
--
Bastián Díaz