Microsoft codenames are the codenames given by Microsoft to products it has in development, before these products are given the names by which they appear on store shelves. Many of these products (new versions of Windows in particular) are of major significance to the IT community, and so the terms are often widely used in discussions prior to the official release. Microsoft usually does not announce a final name until shortly before the product is publicly available. It is not uncommon for Microsoft to reuse codenames a few years after a previous usage has been abandoned.

There has been some suggestion that Microsoft may move towards defining the real name of their upcoming products earlier in the product development lifecycle so as to avoid needing product codenames.

Windows 3.xx/9xEdit

Codename(s) Preliminary name Final name Notes Ref
3.00.55 Windows 3.0 (Windows 89-91)
Janus Windows 3.10 (Windows 3.1) (Windows 92) and Windows 3.11
Sparta (Kato), Winball (Jastro) Windows Plus! Windows for Workgroups 3.1 Windows 3.1 (16-bit) with enhanced networking; designed to work particularly well as a client with the new Windows NT.
Snowball Windows for Workgroups 3.11 Although this release was still 16-bit Windows, it included a 32-bit TCP/IP stack (when running on compatible hardware). Along with Win32s, this was one of the first steps towards moving the Windows desktop to a 32-bit code base.
Cougar/Chicago Windows 4.0 Windows 95 The 32bit protected mode kernel of Chicago (Windows 95) was codenamed Cougar and runs on top of Jaguar (Chicago kernel).
O'Hare Internet Explorer, first shipped in Microsoft Plus! for Windows 95 The codename O'Hare ties into the Chicago codename for Windows 95: O'Hare International Airport is the largest airport in the city of Chicago — in Microsoft's words, "a point of departure to distant places from Chicago".
Frosting Microsoft Plus! for Windows 95
Detroit Windows 95 OSR 2 Named after Detroit, Michigan. A writer for Maximum PC suggested that "Detroit" and other Windows 95-era names were answers to the question posed by Microsoft's "Where do you want to go today?" marketing campaign.
Cleveland/Nashville (96)/Memphis (97) (same as Windows 2000 is codenamed) Windows 4.1 Windows 98 The codename was the key to activating an easter egg in Windows 98:

  • Open the "Regional Settings" control panel;
  • Go to the "Regional Settings" page;
  • Hold the Control key and drag a line with the mouse cursor from Memphis, Egypt (or maybe Cairo, codename of Windows NT 4 - the map is too small to tell) to Memphis, Tennessee. Still holding the Control key, drag another line from Memphis to Redmond, Washington;
  • A window opens with the credits for Windows 98.
  • this codename is also visible from Windows 95 OSR in its version of DOS 7 - before any EXEs or windows is loaded the words: Microsoft (R) Memphis - are loaded into memory, although on the disc they are encrypted.
Georgia/Millennium Windows 4.9 Windows Me Me (ME) stands for Millennium Edition.

Windows NT familyEdit

Codename Preliminary name Final name Notes
AXP Windows NT 3.1 Workstation
June 93 Windows NT 3.1 Advanced Server
Daytona Windows NT 3.5 (Windows 94) and Windows NT 3.51 Named after the Daytona International Speedway in Daytona Beach, Florida.
SUR (Shell Update Release), Cairo (same as Windows 2000 Server Family is codenamed) Windows NT 4.0 Microsoft originally planned for NT 4.0 to be just a simple "Shell Update Release" to integrate the Windows 95 GUI with Windows NT 3.51's kernel.
Wolfpack Microsoft Windows NT Cluster Server 4.0
Hydra Windows NT 4.0 Terminal Server Terminal Server adds "multiheading" support to Windows (the ability to run multiple instances of the graphics subsystem), and the hydra is a mythological monster with multiple heads.

NT 5.0/Menas

Janus (same as Windows 3.1-11 is/are codenamed)

Windows 2000 Professional/Server Family and 64-bit


Windows NT 4.0 Embedded
Neptune Windows 2000 Home Edition


Windows 2000 Datacenter Server
Whistler Windows XP Named after Whistler, British Columbia, where design retreats were held.
Mantis Windows XP Embedded Named after the Mantis shrimp
Freestyle Windows XP Media Center Edition
Harmony Windows XP Media Center Edition 2004
Symphony Windows XP Media Center Edition 2005
Emerald Windows XP Media Center Edition 2005 Update Rollup 2
Diamond Windows Media Center Included in Windows Vista
Springboard Set of enhanced security features, included in Windows XP Service Pack 2.
Lonestar Windows XP Tablet PC Edition 2005
Whistler Server Windows Server 2002,
Windows .NET Server
Windows Server 2003
Bobcat Windows Small Business Server 2003
Eiger, Mönch Windows Fundamentals for Legacy PCs Mönch included additional features for use on mobile devices.
Longhorn Windows Vista Whistler-Blackcomb resort; initially planned as an "interim release" between |"Whistler" and "Blackcomb" (which was "Vienna" and is now Windows 7).
Mojave Windows Vista Spoof codename used for the Windows Vista "Mojave Experiment" marketing exercise.
Quattro Windows Home Server
Vail Windows Home Server 2011 Windows Home Server 2011
Longhorn Server Windows Server 2008
Cougar Windows Small Business Server 2008
Viridian Hyper-V Virtualization update for Windows Server 2008.
Centro Windows Essential Business Server
Blackcomb, Vienna Windows 7
Fiji Windows Vista Media |Center Feature Pack 2008 Windows Media Center TV Pack 2008
Red Dog Windows Cloud Windows Azure Windows cloud services platform
Aurora Windows Small Business Server 2011 Essentials
Quebec Windows Embedded 2011
Chidori Windows 8 Windows 8

The results of Project Midori and Project Singularity were included in Windows 8.

Blue Windows Blue Windows 8.1 Windows 8.1 will be the first mayor update of Windows 8, to be released late 2013.

Windows CE familyEdit

Codename Preliminary name Final name Notes
Pegasus, Alder Windows CE 1.0 (released November 1996)
Birch, Gryphon Windows CE 2.1
Cedar, Galileo, Rapier, Merlin, Stinger Windows CE 3.0 (released April 2000)
Talisker Windows CE .NET Windows CE 4.0 (released January 7, 2002)
Macallan Windows CE 5.0 (July 9, 2004
Yamazaki Windows CE 6.0 Windows Embedded CE 6.0

Visual Studio familyEdit

Codename Preliminary name Final name Notes
Thunder Visual Basic 1.0 The first version of Visual Basic. The standard dialogs and controls created by the Visual Basic runtime library all have "Thunder" as a prefix of their internal type names (for example, buttons are internally known as ThunderCommandButton).
Zamboni Microsoft Visual C++ 4.1 After Zamboni, an ice resurfacing machine.
Boston Microsoft Visual Studio 97 Named for Boston, Massachusetts.
Aspen Microsoft Visual Studio 6.0 Named after the popular ski destination Aspen, Colorado.
Cassini Web Server ASP.NET Development Server The lightweight local Web server that is launched in Visual Studio in order to test Web projects.
Hatteras Visual Studio Team System's Source Control System Named after the Cape Hatteras Lighthouse in the Outer Banks region of North Carolina.
Ocracoke Visual Studio Team System load testing suite Named after the Ocracoke Island Lighthouse on Ocracoke Island, also in North Carolina.
Currituck Team Foundation Work Item Tracking Named after the Currituck Beach Lighthouse in Corolla, North Carolina.
Bodie Team Foundation Server SDK Named after the Bodie Island Lighthouse in North Carolina.
Tuscany Online version of Visual Studio. Currently a research project.
Phoenix A Microsoft research software development kit.
Eaglestone Visual Studio Team Explorer Everywhere This is the name given to the Teamprise suite Microsoft acquired. The product is now named Visual Studio Team Explorer Everywhere
KittyHawk Visual Studio LightSwitch RAD tool aimed at non-programmers.
Rainier Visual Studio .NET (2002) Named for Mount Ranier, a volcanic mountain peak visible from the Seattle area (where Microsoft is based).
Everett Visual Studio .NET 2003 Named after the town Everett, Washington in Washington state.
Whidbey Visual Studio 2005 Named after Whidbey Island in the Puget Sound
Orcas Visual Studio 2008 Named after Orcas Island in the Puget Sound
Dev10 Visual Studio 2010
Rosario Visual Studio Ultimate 2010 (formerly Team System or Team Suite)

SQL Server familyEdit

Codename Preliminary name Final name Notes
Sphinx SQL Server 7.0
Yukon SQL Server 2005 (Version 9)
Katmai / Akadia SQL Server 2008 (Version 10)
Kilimanjaro SQL Server 2008R2 (Version 10.5)
Plato Olap Services 7.0 This was the first release of Microsoft Analysis Services
Blue SQL Report Designer 2.0 This is the stand alone release of the tool for SQL Server Reporting Services.
Denali SQL Server 2012 (Version 11)
Juneau SQL Server Data Tools Will be included in the next CTP of SQL Server "Denali"
Crescent Power View A data visualization tool that will be included in SQL Server "Denali"

Other server productsEdit

Codename Final name Ref
Hermes Microsoft System Management Server 1.0
Catapult Microsoft Proxy Server 1.0
Geneva Active Directory Federation Services

Experimental operating systemsEdit

Codename Preliminary name Final name Notes
Singularity Singularity Experimental operating system based on the Microsoft .NET platform, using software-based type safety as a replacement for hardware-based memory protection.


Codename Preliminary name Final name Notes
Lightning, Project 42 Next Generation Windows Services Microsoft .NET v1.0 Project Lightning was the original codename for the Common Language Runtime in 1997. The team was based in building 42, hence Project 42. "Next Generation Windows Services" appeared in the earliest press releases about the upcoming platform.
Roslyn Next Generation C# compiler Unspecified, speculative to Microsoft .NET v5 or .NET v6 compiler Roslyn is the next generation of design guidelines for developer tools, which is often highlighted by a C# compiler being written in C# (currently it is C++) and being offered as a service. This would enable scenarios like C# having its own version of the JavaScript eval command ultimately leading to meta-programming. Mono has had a similar feature since early on its life
Project 7 Codename for early .net academic recruiting program. 7 was a prime factor of 42.

Xbox and Xbox 360Edit

Codename Preliminary name Final name Notes Ref
DirectX Box Project Dakota Xbox The original codename for the Xbox.
Natal Project Natal Kinect Motion sensitive control system.
Xenon Xbox 2 Xbox 360
Durango Xbox 720 Xbox One


Codename Preliminary name Final name Notes
Acropolis Application framework for Smart Clients
Aero Diamond Used during the development of Windows Vista to describe a set of advanced user interface effects for the Desktop Window Manager to be introduced after Vista's release.
Albany Microsoft Equipt Albany is Microsoft's all-in-one, subscription-based service for office, communication, and security software.
Alexandria Zune Marketplace An online music store.
Argo Zune A digital media player.
Atlanta A cloud service that monitors Microsoft SQL Server deployments
Atlas ASP.NET AJAX An implementation for ASP.NET of Ajax native to the .NET Framework 2.0.
Avalon Windows Presentation Foundation Graphical subsystem released as part of .NET Framework 3.0.
Bandit Schedule+ 1.0 Microsoft's first Personal Information Manager.
Blackbird An online content-authoring platform centered around the concept of distributed OLE (Object Linking and Embedding) and meant to be an alternative to HTML. The developer tools were originally released in beta and some titles were made available on MSN before it was scrapped in favor of web development around ASP and ActiveX and the designer was refashioned into Visual InterDev.
Marvel The Microsoft Network The classic version of MSN, originally as a proprietary, "walled garden" online service.
Bullet Microsoft Mail 3.0 Microsoft's first LAN-based email product written in-house. (Microsoft had earlier purchased Intermail for AppleTalk networks and Network Courier for PC networks.)
Budapest Microsoft Office Communicator Web Access 2005
Catapult Microsoft Proxy Server 1.0
Cider Visual Studio designer for building Windows Presentation Foundation applications. Meant to be used by application developers.
Cirrus Access 1.0
Concur Aims to: define higher-level abstractions (above "threads and locks"); for today’s imperative languages; that evenly support the range of concurrency granularities; to let developers write correct and efficient concurrent applications; with lots of latent parallelism; that can be efficiently mapped to the user’s.
CRM V1.0, Tsunami Microsoft CRM version 1.0 The platform was initially code named Tsunami, but once the decision was made to make it an actual product it was just changed to the initials as the initials were enough of a code name.
D M Modelling language
Dallas Easily discover, purchase, and manage premium data subscriptions in the Windows Azure platform.
Darwin Microsoft Installer Windows Installer
Danube Phase I Microsoft CRM version 1.2
Danube Phase II Microsoft CRM version 3
Deco Microsoft PhotoDraw
Dorado Zune PC Client
Dryad A Microsoft Research project which aims to design a platform to make developing applications for large-scale distributed computing easier.
Godot Microsoft Layer for Unicode Named after the play Waiting for Godot (centered around the failure of a man named "Godot" to appear and the endless wait for him), because it was felt to be long overdue.
Greenwich Real-Time Communications Server 2003 Microsoft Office Live Communications Server 2003
Indigo Windows Communication Foundation An application programming interface (API) in the .NET Framework for building connected, service-oriented applications
Istanbul Microsoft Office Communicator 2005
Kumo Bing Microsoft's set of features improving Live Search search engine
Clarity LINQ Language Integrated Query Language extensions to expose query syntax natively to languages such as Visual Basic .NET and C#
Maestro Microsoft Office Business Scorecard Manager 2005.
Media2Go Windows Mobile software for Portable Media Centers Platform built on Windows Mobile found on portable media players.
Metro XML Paper Specification (XPS)
Milan Microsoft Surface Table-top style computer with multi-touch touchscreen interface.
Mira Windows CE .NET-based technology for smart displays.
Monaco Music-making program similar to Apple's GarageBand application
Monad MSH, Microsoft Shell Windows PowerShell Monads, according to philosopher Gottfried Leibniz's monadology, are the ultimate elements of the universe, individual percipient beings, and MSH is similarly composed of small, individual modules the user puts in interrelation.
Morro Microsoft Security Essentials MSE was codenamed after the Morro de São Paulo beach.
Origami Ultra-Mobile PC
Omega JET Engine ISAM database engine used in Microsoft Access, a desktop database management system.
Opus Word for Windows Word for Windows 1.0 for Windows 2.x, named after the penguin in the comic strip Opus.
Palladium Trusted Windows Effort to develop a small, very secure operating environment within Windows, including curtained memory, trusted input, and graphics. Project renamed to Next-Generation Secure Computing Base, and was never fully implemented.
Pinball High Performance File System Implemented as an Installable File System when IBM and Microsoft were co developing OS/2.
Volta C# to JavaScript compiler.
Softsled Software based Media Center Extender.
Springfield Microsoft Popfly Website in Alpha testing stage providing mashup and webpages creation tools, with publishing as Rich Internet Application option.
Tahiti Supposedly a family of multi-core technologies including an operating system, applications and development tools designed to make better use of today's multi-core CPUs. It is believed that Midori may be a part of this suite of new Microsoft technologies.
Tahiti Microsoft SharedView A screen sharing tool which allows users to take over sessions and interact with remote desktops. No audio or conference facilities.
Tahoe Sharepoint Portal Server 2001.
Titan, Kilimanjaro Microsoft CRM version 4 Was originally Kilimanjaro but changed to Titan as Kilimanjaro was too difficult to spell.
Jakarta Visual J++
Jasper “Jasper” provides a programming interface to your data that is well-suited to rapid development. When a Jasper program runs, Jasper connects to the database, determines the database schema, and generates corresponding data classes. This generation step does not result in source files; the data classes are compiled in-memory and available for use within the running program.
Jolt Silverlight 1.0
Paxos Silverlight 1.1
Wolverine TCP/IP Stack for WfW 3.11 Named after the Wolverine the character from Marvel Comics.
Oslo set of SOA - technologies
Velocity Distributed Caching for .NET
Zurich Azure Microsoft's Cloud platform (See Azure Services Platform)
Metro Windows Phone 7 user interface, largely based on Zune HD
Mango Windows Phone 7.5 Windows Phone 7, largely based on Zune HD

External linksEdit