I don't even really know if the title is the best way to explain what I'm trying to do, but anyway...

We have a web app that is being ported to a number of DB backends via MDB2. Our unit tests are pretty lacking at the moment, but our internal users are pretty good at knowing what to test to see if things are broken.

What I'm 'imagining' is a browser plug in (don't really care which browser it is for) or a similar system that essentially takes every event from one window and 'mirrors' it in the other browser/s. The reason I'd like this is so that I can have various installations that use different DB backends, and have the user open a window/tab to each installation. From there, however, I'd like them to be able to 'work' in one window and have that 'work' I occur at the same time in each of the 'cloned' windows. From there, they should be able to do some quick eyeballing of the information that comes back, without having to worry about timing differences and so (very much).

I know it's a big ask, but I figure if anyone knows of a solution, I'd find it here...

Any thoughts?