There’s more to this.
Here is the full original SDK package:
messengerActivitySDK.zip (609.7 KB)
A PowerPoint deck from the original Messenger Developer Group Product Planner Scott Swanson (the guy behind P4 Activities):
BuildingMSNMessengerActivityApplications.zip (263.8 KB) Also on the web, although the not-really-important notes aren’t there. If anyone has access to BetaArchive the PDC 2005 discs would contain the video of the presentation.
A sandbox environment made to test activities out:
Sandbox.rar (94.5 KB)