tl;dr: Theme translations and language packs are coming to WordPress.org and they’re awesome.
Howdy all you wonderful themers and theme reviewers,
The meta team has been working hard to enable theme and plugin translations on translate.wordpress.org. For themes, we plan on importing all active themes into WordPress.org – that is, any theme updated within the last two years. We expect to import them in the next few days or weeks, at most. This will involve importing ~1500 themes, which, combined, have about 315,000 total strings. After duplicates, the number drops to only 80,000 unique strings.
Below are some things you might want to know.
Why do I want WordPress.org managing translations for my theme?
WordPress.org provides translations in dozens of languages and is ever expanding as new contributors join. (There are currently 140 locales on translate.wordpress.org, but not all are active.) While you may have translated your theme into a few languages (or none!), there are likely more translators on WordPress.org in more languages.
But that’s not all! Themes in the WordPress.org directory will be able to take advantage of language packs! That means smaller download sizes for users, because themes will no longer need to ship translations. Eventually, we also plan to give priority to localized themes in localized directories; e.g., someone searching the Romanian theme directory will see Romanian themes prioritized over English-only themes.
What if my theme already ships translations?
Translations that are already shipped in themes will be initially imported into translate.wordpress.org. Again: we’ll import the strings and the translations on the initial import. We won’t continue to do that because the end goal would be for theme authors to remove the translations from their download, allowing language packs to fill the void.
What if I don’t want to use WordPress.org to manage translations for my theme?
Then you don’t have to! Translations shipped in a theme take precedence to language packs. If you continue to ship translations with your theme, WordPress will ignore the language packs. However, if a translation is available in a language your theme doesn’t support, WordPress will use the language pack for that language.
How do I add support for translations and language packs?
@Otto42 wrote up a great post on the topic back in 2013. (Wow, it’s been a long time!) There’s also a great page in the theme developer handbook which walks through how to internationalize your theme.
To fully support language packs, you’ll want to remove translations from your theme in your next update.
What if I want my translators to approve translations on WordPress.org?
We’ve written up a plan for working with the polyglots team to enable this. There will be some initial pain in adding new, project-specific (aka theme-specific) translation editors, but afterwards your translators will join a growing group of WordPress translators and help make the entire ecosystem better.
Just ask! We’ll watch this thread and answer any questions you might have.