Arun Nanda, Mike Jones, and others both at Microsoft and Ping have been working very hard for a long time now to make sure the profile we used to build our prototypes, and then our product, was being fully shared with everyone else who wanted to interoperate. This has also involved an ongoing attempt to make sure the profile was clear enough to be useful.
Today I'm posting new versions that I think are a lot clearer (let me know!) First, here is A Guide to Supporting Information Cards within Web Applications and Browsers as of the Information Card Profile V1.0. I think anyone adding InfoCards to their site will find this document useful.
In addition I'm putting up two documents intended for people who really want to get into the details of how to implement the underlying toolkits and platforms. Don't feel compelled to read them if you aren't doing this type of work! They are part of the process of working with our colleagues in OSIS, Higgins, etc – those building Identity Selectors and the system software that powers managed card providers and claims transformers. The papers will also be of interest to academics and people who really like to get way down into how things work. You should begin with A Guide to Interoperating with the Infomation Card Profile V1.0. I'll post the second document (the normative technical reference) in a couple of days.
I'm beginning by putting these docs up here so everyone in the identity community can get access to them ASAP. Ultimately, they will appear in many other places, including MSDN.