Over the last few days I’ve been working what is basically a demonstration and debugging page for the SharpSTS site to allow people to dynamically build an Information Card object tag, then submit a card to it and see the results. It was problematic to say the least, with a major part of the problem being there is no real documentation about how the object tag is supposed to expose itself to a scripting environment.
In order to detect information card support without Firefox bringing up its additional plugin required information bar you cannot embedded an information card object tag in the page; you need to create it via javascript after the page as loaded. I took this a little further with the tag builder and produced what Axel, the maintainer of the Firefox Identity Card extension, deemed "kung fu". After a bunch of emails back and forth Axel has updated the plugin to support my jiggery pokery (thanks are obviously due here). At the moment the DigitalMe doesn’t work with the extended dynamic creation things I am doing (and my geek skills are weak; I can’t even get it installed inside SUSE in a Virtual PC).
The lack of an easy detection method is painful. There is discussion around an X-Id-Selector header; and debate over what it should contain and how the capabilities should be indicated; but until that happens it will be kung-fu or nothing.