OCS employs a robust plugin architecture, making it easy for developers to add new functionality without making changes to core code. A number of plugins come pre-installed by default. Plugins fall into the following general categories: generic plugins; import/export plugins; payment plugins; block plugins; citation format plugins; and theme plugins.

Some plugins simply need to be enabled to work, while others need varying levels of configuration. For more information, refer to the documentation included with each plugin, found within OCS' plugin directory (/path/to/install/plugins).