Apache OpenOffice - Full Installation vs. Language Pack
By default Apache OpenOffice is offering a single language when installing a full installation. Full installation means that all application modules (Write, Calc, Impress, etc.) are available. The term does not belong to languages.
When you want to use one or more languages in OpenOffice for the user interface (for example, menus, dialogs and messages ) and help topics then it is recommended to use language packs. The idea is to have a base installation for, e.g., English (US) and additional languages on top without a need to install a full installation for every language. For this every language pack has to be installed over a full installation. Important is that the same version number and platform has to fit to the base installation (for example, it is not possible to install a language pack from release 4.1.9 over the base installation of 4.1.8).
Language packs contain only resource files to show menus, dialogs, messages, etc. in your favorite language but there is no program logic. In case text is not fully localized some elements of the user interface or help topics will display in English as default language.
After the language pack is installed the new language can be switched via the menu "Tools - Options - Language - Settings - Languages - User Interface".
Currently dictionaries are not included in language packs, only in full installations. This limitation is a technical issue still to be fixed, see Bug 124473 for more details.
Users who install language packs must take an extra step to manually download the matching dictionary from the Extensions website.
Dictionaries get improved independently of the release schedule of OpenOffice and are offered separately. They can be updated at any time when new versions are released.