The official documentation is at: http://docs.alfresco.com
Alfresco_Opencms is an Alfresco add-on that permits you to replicate one Alfresco folder into one Opencms folder. And thus, every time that you create/modify/delete the content in the Alfresco folder the same content is created/modified/deleted in the Opencms folder.
More info in: http://alfresco-ocms.sourceforge.net/
Note: the project on SourceForge has last been updated in 2007, quite a few years old, and is on version 0.0beta. It is probably not the most efficient solution due to recent updates in OpenCms 8 and it's features and new interfaces (CMIS support, etc.).