OpenAnnotate is a browser-based tool that allows users to create, share, and view annotations on a document within your ECM environment (Documentum, Alfresco, others...).  OpenAnnotate supports annotating with sticky notes and drawing tools including lines, arrows, circles, and rectangles.

OpenAnnotate: Reducing Software and Maintenance Costs for Online Review and Annotation

• No Client Machine Dependencies
  OpenAnnotate allows users to view and annotate documents directly in their browsers without dependencies on Adobe Reader or other viewing applications. OpenAnnotate can also produce annotated PDFs that can be viewed with Adobe Reader.
• Leverages Enterprise Content Management (ECM) Systems
  TSG’s OpenContent Web Services are utilized to store and retrieve annotations from an Enterprise Content Management system of your choice (i.e. Documentum, Alfresco, SharePoint, etc.). Integrated content caching and page caching provides users with quicker response times and less rendering waits.
• Integrates with Documentum Webtop and Alfresco Share
  Connectors are available for both Documentum Webtop and Alfresco Share and TSG's  High Performance Interface (HPI) which is designed to run on an Enterprise Content Management system of your choice. OpenAnnotate will even display annotations originally generated using Documentum PDF Annotation Services.
• No Licensing Costs
  TSG does not charge a licensing fee to use OpenAnnotate
• Secures Document Distribution
  Users only have access to image renditions of individual document pages preventing them from downloading an entire document and distributing it outside of the managing application.