Each of these browsers has its own PDF viewer. Some of them can optionally be set up, by the end user, to use Adobe Reader instead.
(Don't overlook Windows 8 IE10, which defaults to running Windows 8 Reader.)
And don't overlook the mobile browsers on iPad, iPhone, Android...
You might try insisting that your users use Adobe Reader.
Thank you for quick answer.
Is it possible to detect programmatically which pdf viewer is set by default by the browser so I can notify the users about it?
No, I don't think there is any way to do that.
I thought so.
You can use a script that looks at the different viewer properties of the app object (viewerType, viewerVariation and viewerVersion), as well as the external property of the Document object. Of course, there's no guarantee that these browser plugins are handling these properties correctly, or at all...
You can embed this code in your file and see what shows up... If app.alert() isn't working you can try using it to populate a text field.
app.alert("doc.external = " + this.external + "\napp.viewerType = " + app.viewerType + "\napp.viewerVariation = " + app.viewerVariation + "\napp.viewerVersion = " + app.viewerVersion,3);