Gettext has most of the features needed, when translating software, like plurals, comments by developers and translators and fuzzy strings. There are projects t

Gettext has most of the features needed, when translating software, like plurals, comments by developers and translators and fuzzy strings. There are projects that even use it for documentation purposes, like fedora. Another good format for i18n is the TS format used by QT (http://doc.qt.nokia.com/stable/linguist-ts-file-format.html http://doc.qt.nokia.com/stable/linguist-ts-file-format.html).