The latest attachment viewer with source has been posted to OpenNTF, you can watch the video I posted a few days back to see how it works. The OSGI extension model is also complete so anyone can now extend the viewer with more file types. Hopefully the many implementations I have in the project will be good enough documentation for others.
You can drag the icon below to your My Widgets panel in Lotus Notes 8.5.1 or above. You can watch a video that shows how to do this here.
Any issues with this version please email me directly – bob at balfes.net
For reference, I have re-posted the video: