Link Details

Could do OpenNMS in Flex and get a desktop UI experience - better than most X11 UIs as Flex SDK has a lot of features that are much easier and quicker to use and yield better result. Plus you would no longer be stuck battling browser differences per HTML/JavaScript.

While keeping the deployment from a web server approach, you could write a very minimal AIR front-end that gets installed on the desktop. With Flex SDK 3.2 you can then use SWFLoader to load your app from the web server as a sub-application running in a remote sandbox.

The AIR component of your app could be used to extend with enhanced capabilities. The remotely loaded web core would contain the bulk of functionality and might use Flex Charting package to do dashboard displays, etc. Then the AIR component could implement extensions such as a systray icon and an "Outlook" style notification system, or a user presence detection, or, of course, access SQLLite or file APIs. There is a bridge that can be used for the sub-application to communicate with the host and objects can be marshalled to and from the sandboxes.

To the user this all looks like a single, seamless application. If they use a browser and go to your app with a URL they get one level of functionality that is feasible in a browser sandbox. If they take a little more time and install your AIR front-end, they now get a significantly enhanced application in terms of more features.

Oh, and if you take the Flex approach, you might consider using Google's flexlib as it has support for MDI child windows. You can do these in both browser and AIR but in AIR you can set the native window to transparent and fullscreen. The child windows float on the user's desktop and can click through to other app windows, but when the AIR app is minimized, they all go away as a single layer. This behaviour is just like a Mac OS X MDI application but of course is portable via AIR across Windows, Linux, and Mac.