Microsoft Office Sharepoint Server (MOSS) is a collection of collaboration and document management products from Microsoft. It allows organizations to aggregate and organize information in a central web application. MOSS runs on top of Windows Sharepoint Services (WSS) and integrates closely with Microsoft Office applications, enabling users to directly edit documents stored in Sharepoint libraries. It provides capabilities for enterprise content management, web content management, records management, and web 2.0 collaboration through features like blogs and wikis.