Messenger services (tabs)

[Will Program For Food]

Hi,
MSN Messenger has tabs for various services such as Calendar (no longer
free, therefore no longer used), stock quotes etc.... Is there a document
that describes how one can "offer" MSN messenger "tab" services? I'm
actually not thinking on "offering" but implementing so that I can have
access through it via my MSN, it would be rather convenient considering my
MSN is on most of the time.

Regards,
Emilio