A while ago Mary Jo Foley started with the article series - A (Microsoft) code name a day - here are some of them which are a little less know (but definitely not less interesting):
- Harmonica - Best guess on what it is: A P2P data synchronization service that could be key to Microsoft’s cloud-computing vision.
- Greenland - Best guess on what it is: WS-Management Protocol 1.1
- Jasper or Dynamic ADO.Net - definitely take a look at this one - download the Jasper CTP or at least read about it on the ADO.Net blog
- Astoria - Best guess on what it is : A set of technologies allowing applications to expose data as a data service that can be consumed by Web clients within a corporate network and across the Internet. Astoria is one component of Microsoft’s “data-in-the-cloud” strategy. Also take a look at Introducing Project Codename Astoria
Check out the complete overview of Microsoft Codenames on ZDNet