The PHP Manual has over 30 translations already setup, but due to inactivity many have been taken offline. The odds are high that your language has already started a translation, but for various reasons it's no longer being updated or shown at php.net.
If you're interested in helping translate a specific language, then please read the translation section of the Guide for Manual Contributors and contact the appropriate mailing list. Whether or not your language is shown below, you are very welcome to help translate the PHP Manual from English to another language.
The following list of languages already contain SVN modules, and will show up on the documentation development server. Warning: These translations are considered outdated, so content within each may be completely wrong or insecure!