title: Need a framework for a notification/dashboard system?
body: <p>I've been asked to implement a notification system in a Cloud Java application.  The premise is that administrators or components of the application can send either specific messages to individual users, or broadcast announcements to all users.</p>
  
  <p>Notifications would be categorized by severity, type (outages, new services, etc.), and corresponding component.</p>
  
  <p>Users would be able to select types and components they're interested in, and how they'd like to receive those notifications (by e-mail, just shown on dashboard, SMS, etc.).  Users could acknowledge or delete notifications, so they won't show up for that user anymore.</p>
  
  <p>Although I'm sure this would be interesting to implement from scratch, it just feels like there should be an existing system, Apache project, commercial project, etc. that does just this and would avoid me having to reinvent the wheel.</p>
  
  <p><strong>My question is:</strong> Can anyone recommend a framework for notification tracking that could be integrated into an existing application and automatically handle all the back end stuff?  Commercial or open source are fine, as long as the licensing terms are commercial friendly (no GPL or LGPL, please).</p>