Hi Anne
we aren't taking this as criticism but likewise we aren't aware of any issues especially with Chrome e.g. the thumbnail viewer in the page types example
www.nottingham.ac.uk/toolkits/play_8203&page=27
works fine in Chrome for me and shows the text overlay just fine. Does that example not work for you? Can you share a link to one of your examples where this doesn't work?
Also what interactions don't work? What happens? Examples/screenshots/steps to replicate?
It certainly shouldn't be necessary for your users to switch to Firefox from Chrome or IE 10 or later and in my experience even IE 9 should be ok in most cases for viewing rather than authoring and certainly IE 10 or later should be fine.
This is a public forum so it's important that anyone else reading this should not get the idea that Xerte output only works in Firefox - that's certainly not our experience and we would hear from many more users if that was the case. If there are specific examples we would want to investigate and resolve any issues but as we've said we test regularly in all modern browsers and versions so would need specific examples with links and detailed descriptions and screenshots to troubleshoot.
HTH
Ron