OpenOffice offers a complete framework allowing it to be enriched. OpenOffice allows for both "extensions" and "templates".
An extension is a third party tool that brings OOo new functions. This can be done through addons, addins, deployed by UNO packages.
Templates are document setups designed for specific uses.
The native-lang projects are welcomed helping translating all of these resources. The OOo wiki can be used to provide translation of all the materials found here and now contains the majority of information.
Join the user mailing list if you're willing to share your extensions and need help : users-subscribe@openoffice.apache.org
Join the dev mailing list for any questions related to developing extensions : dev-subscribe@openoffice.apache.org
(See the Apache OpenOffice mailing list page mail subject tags explicitly for extension related development questions.)