As far as IE, my understanding is you have to try and instantiate an ActiveXObject and then check this succeeds, and you can then query the version through the instanced plugin... nothing particularly exciting.
But on Firefox (and I think other NPAPI browsers) you can check for installed plugins and get the DLL name, etc (on Windows at least). What exactly <em>can</em> I find out about installed plugins other than if it exists? Plugin file name, anything else?
edit: And, <em>does</em> IE support <em>any</em> way of querying plugins without creating an instance, in newer versions?Answer1:
For Gecko, the properties are <a href="https://developer.mozilla.org/en/DOM/Plugin" rel="nofollow">listed on MDN</a>. On WebKit, you only have the ones labeled
DOM 0 on MDN (although there is a proposal to add the version info to WebKit as well).
Take a look at the
navigator.plugins array, there you'll find a lot of info :)