It is possible to add more capabilities to Apache OpenOffice with the use of extensions. The main page to find extensions is the following:
On that page it is possible to choose from spell check dictionaries and grammar checkers up to tools that connect Writer to symbolic algebra systems.
It is possible to administer the extensions from Tools → Extension Manager
The link "Get more extensions online" will open the Internet browser predefined by the operating system on the already mentioned page for extensions.
Theis to install extensions already downloaded to a folder on your system.
Selecting an extension from the list it is possible to view its detail, deactivate or even uninstall it completely.
Thebutton will check if new versions of installed extensions are available.
Some extensions could need to restart Apache OpenOffice completely after installing them. An example of those extensions are the dictionaries.
Some extensions could depend on external libraries or programs. For example, several extensions depends on a Java runtime to run.
Some particular extensions may depend on the operating system.