Operating Systems
Chicago – Windows 95
Detroit – Windows 95 OSR 2
Memphis – Windows 98
Millennium – Windows ME
Daytona – Windows NT 3.5
Janus – Windows 2000 64 Bit
Whistler – Windows XP
Bobcat – Windows Server 2003 Small Business Edition
Mantis – Windows XP Embedded 5.1
Freestyle – Windows XP Media Center Edition
Harmony – Windows XP Media Center Edition 1.5
Longhorn – Succesor of Windows XP
Blackcomb – Succesor of Longhorn
Exchange Servers
Osmium – Microsoft Exchange Server 5.5
Platinum – Microsoft Exchange 2000 Server
Titanium – Microsoft Exchange 2003 Server
Kodiak – Microsoft Exchange 2005 Server
SQL Servers
Starfighter – Enterprise Managaer SQL-Server
Hydra – Microsoft SQL-Server 6.5
Sphinx – Microsoft SQL-Server 7.0
Shiloh – Microsoft SQL-Server 2000
Yukon – Microsoft SQL Server 2005
Liberty – 64Bit-Edition von SQL-Server 2005
Other Servers
Hermes – Microsoft Systems-Management-Server 1.0
Opal – Microsoft Systems-Management-Server 2.0
Topaz, Emerald – Microsoft Systems-Management-Server 2003
Ruby, Diamond – Successor of SMS 2003
Greenwich – Realtime Comunication Server
Catapult – Microsoft Proxy-Server 2.0
Comet – Microsoft Internet-Security & Acceration Server 2000
Tripoli, Tivoli – Microsoft Index-Server
Plutonium – Microsoft Commerce-Server 4.0
Sable – Microsoft E-Commerce Server 2001
Tahoe – SharePoint Server 2001
Bobcat – Microsoft BackOffice Server 2002
Latinum – Microsoft BizTalk-Server 2000
Other Codenames
Gecko – Microsoft Internet Explorer 5.0
Texas – MSN 8 client
NGO (Next Generation Office) / Office.NET / Office11 – Microsoft Office 2003
Office10 – Microsoft Office.XP
Opus – Microsoft Word
Boston – Visual Studio 6.0
Everett – Microsoft Visual Studio.NET 2003
Rainier – Microsoft Visual Studio.NET
Dolphin – Visual C++
Wings – Visual C++ for Mac
Rotor – Common Language (CLI)
XDocs – InfoPath 2003 (Part of Office 2003 system)
Whidbey – Visual Studio .NET 2005
Utopia – MS BOB
Thunder – Microsoft Visual Basic
Freon – Sucsessor of X-Box
Fahrenheit – Direct X
Fusion – Technologies for DLL improvements
Kagera – OLE-DB Provider for ODBC-Data
Lightning – .NET Common Language Runtime (CLR)
Luna – Theme technology for Windows XP
Magic Carpet – Passport-Technologien
Touchdown – Public folders for MS Exchange
Wolfpack – Windows Cluster-Services
Marvel – Microsoft Network (MSN)
Gecko : The popular name for the cross-platform and standards compliant layout engine used in Mozilla and Netscape 6.
Maybe the Netscape fellows intended to use it as a pun or something?