There are others, but this is most used: Poedit, a cross-platform gettext catalogs (.po files) editor.
The Formats
- .mo stands for Machine Object
— compiled export of the .po file which is used by WordPress - .po stands for Portable Object
— editable text file with the translations strings
— based on the master .pot file, using Update from POT file PoEdit function
— some folks distribute this as a master file, but it should be used only for translations - .pot stands for Portable Object Template
— editable text file used to grab all the translatable strings from WordPress itself and Themes and Plugins, using Update from Sources PoEdit function
The Procedure
- Duplicate the .pot file and rename it to plugin-basename-lang_COUNTRY.po
- Example for the referenced plugin case: subscribe-reloaded-pt_BR.po
— pt_BR means Portuguese Brazil, but many languages don’t have a country variation…
— you’ll have to fill in with your own language - WPLANG in wp-config.php file must be set to your language, e.g., pt_BR
- Every time you save the .po file, PoEdit automatically generates a .mo file, which is the one WordPress uses and basically the only one you need to upload
Observations
- If you do a full or a decent partial translation of the Digital Publication plugin, submit it to the WP Publishing plugin author so he can include it in the Repository and you get credited for it
- Don’t forget to make a backup of your translation, because if you upgrade WordPress Publication plugin, your file will be lost