The official documentation is at: http://docs.alfresco.com Alfresco offers true Open Source Enterprise Content Management (ECM) - Document Management, Collaboration, Records Management, Knowledge Management, Web Content Management, and Imaging.
Alfresco uses best-of-breed open source technologies such as Spring, iBatis, Solr, and LibreOffice. Alfresco supports modern standards such as CMIS and REST. It is easily extendable with the use of webscripts. And it exposes makes it easy to work with content using standards such as CIFS, NFS, FTP, WebDAV, SharePoint Protocol, SMTP, and IMAP.