After reading the session synopsis’ for the PDC, I realized how many codenames Microsoft uses for their upcoming technology. So I made a list:

• indigo
• atlas
• longhorn
• yukon
• whidbey
• avalon
• orcas
• blackcomb

I realize some of these are no longer used by MS, but I still see them referenced.

Update: Found this Codename Lookup Chart along with the this Wiki.