|Kernel version||NT 6.0|
|CPU Architecture||x86, x64, IA-64|
Longhorn was the codename for the planned successor of Windows XP. The project was reset and replaced with a new project - Longhorn Omega-13 which was later renamed Windows Vista. Early builds of Windows Vista were often referred to as "Longhorn", causing confusion.
One of the original - and largest - changes is that, with "Longhorn", the .NET Framework would be integrated into the core Windows platform, deprecating the traditional Win32 API. During development, portions of the operating system were rewritten, causing memory leaks and instability, particularly in Windows Explorer.
Contrary to popular belief, most of the early builds of "Longhorn" are not based on Windows XP, but Windows Server 2003 release candidate code. The xpclient release branch, dedicated to XP, spun off from the main branch in 2001. The main branch continued to compile Server 2003 builds, until the dnsrv branch, dedicated to Server 2003, spun off from the main branch in 2002. At that point, the main branch began compiling Longhorn builds.
"Longhorn" was chosen as the codename for the operating system to represent its initial status as an internim release between Windows XP (codenamed "Whistler") and "Blackcomb". Whistler and Blackcomb are names of mountains in British Columbia, Canada, and Longhorn is the name of a saloon located in between the two mountains, representing the operating system's initial status as an internim release between the two products. Bill Gates would later state that this choice for a codename of the operating system was "a bit random".
- First build to include Desktop Composition Engine (basic window transparency effects).
- First build to include Sidebar.
- A new theme, Plex, was introduced.
- Internet Explorer was updated to version 6.05.
- A new display settings applet was introduced, based on the Windows Presentation Foundation.
- New wallpaper.
- Updated a bit Plex.
- Animated files and folders icon in the Explorer.
- Introduced application MyTVApp.
- Sidebar is enabled by default.
- The only build to contain both Media Center and Tablet PC editions.
- Removed Classic View from Control Panel.
- New Setup UI and OOBE.
- Using install.wim during the installation.
- Updated wallpaper.
- New Setup UI.
- Updated Wallpaper and Screen saver.
- Some improvements in Internet Explorer.
- Updated Plex theme.
- Parental Controls introduced.
- New bootscreen.
- New wallpaper and logon screen.
- Windows Messenger was updated to version 5.0.
- Introduces a working DCE.
- Skipped OOBE and changed watermark to "Longhorn Professional".
- Ctrl+Alt+Delete now opens a security interface instead of Task Manager.
- Some changes in the Setup UI and Plex theme.
- Wallpaper and logon screen were updated.
- Outlook Express updated.
- Introducing the Game Library.
- Introducing the Sync Manager.
- The first build that had Home Edition SKU.
- Bugfixes from earlier builds.
- New wallpaper.
- File a Longhorn bug added.
- My Computer icon is updated.
- Some improvements in the Internet Explorer.
- The first build that had ia-64 version.
- Introduced Aero Theme.
- Changes in the Setup UI.
- Some updates in the Explorer.
- Uses an older code.
- A bit changed Setup UI.
- Plex theme is replaced by Slate (only lab06_n compile).
- New logon screen, wallpaper and boot screen.
- New Task Scheduler.
- "Start" is removed from the Start Menu button (when sidebar is enabled) and "My" in the Start menu is removed everywhere.
- New Setup UI, screen saver and logon screen.
- Windows Media Player 9 is updated.
- The first build that had a checked version.
- The first build that had 64-bit version.
- Patched some network bugs.
- Added Jade Theme.
- Updated icons in the Start Menu.
- Introduces DWM and Aero.
- The first build that included full DWM and Aero. However, it requires some work in order to enable it.
- The only build that had Animated Preview Pane Aurora. Requires patching to show up in Explorer.
- Removed many core features.
- Starting this build introduces many bugs, ex. BSOD on Safe Mode.
- A bit updated Setup UI.
- New wallpaper tree, reverted some icons with XP ones.
- Removed few Sidebar features.
- New setup text.
- Reverted some core features.
- Fixed WordPad.
- The last Longhorn build before reset.
- Fixed Windows Classic theme.
- Early version of UAC called Windows Security.
- Early version of Movie Maker 3.0.
- New Avalon-based Power Options panel.
- New Text To Speech panel.
- Last build that does not need ACPI to work since it uses NTLDR.
Several different logos were created throughout the development of "Longhorn". Early builds used 2D and 3D representations of a longhorn bull; later builds included white or glass versions of the Windows flag.
Concepts, presentations, demos and prototypes
- Earliest concepts (2002, 2003)
- MSX "Longhorn Days" (2003)
- Amazon.com demo (PDC 2003)
- Get Users to Fall in Love With Your Software - Hillel Cooperman's demo from PDC 2003 (video)
- Business solutions enabled by Longhorn technologies by Carter Maslan (2004, mockups only)
- For server builds, see the Windows Server 2008 page.
- See Windows Vista.
- Athens PC
- WinHEC 2003
- PDC 2003
- WinHEC 2004
- Windows Sidebar
- Desktop Composition Engine (Longhorn)
- Desktop Window Manager
- Friendly Fire
- Self-Host Vote
- Next-Generation Secure Computing Base
- The very beginning. Retrieved on 2 April 2021.
- Whistler Vacation Tips. "Windows Blackcomb: See Why Bill Gates Loves Whistler"
- Thurrott, Paul. "Windows 'Longhorn' FAQ"
- Thurrott, Paul. "Road to Gold: The Long Road to Windows Vista Part 1: 2001-2001"
- Levy, Steven. (November 23, 2003). "He's Still Having Fun"
- The Pillars of Longhorn
- The Pillars of Longhorn: Living La Vida Longhorn (Longhorn Foghorn)
- Introducing Indigo: An Early Look, February 2005 (May 2005 version from the authors' site)
- Longhorn Developer Center Home: User Experience (Aero)
- A First Look at Writing and Deploying Apps in the Next Generation of Windows
- Jim Allchin - The Longhorn Update
- Paul Thurrott's SuperSite for Windows: The Road to Windows "Longhorn" (last updated 13 November 2002)
- Aurora & Aero | Microsoft Longhorn
- Hacking Avalon – 1: Disable it
- Hacking Avalon – 2: Port it | Microsoft Longhorn
- Hacking Avalon – 3: Compiling xaml
- Managed C++ and the Longhorn Shell
- .NET framework
- Help center
- The Longhorn Kernel-Mode Timebomb
- Aborted Longhorn concepts/features
- Windows "Longhorn" features present in Windows Vista
- UX.Unleaked Grabberslasher's blog that describes several unleaked "Longhorn" builds
- Jim Allchin’s Mac message: The full text (leading up to the reset)
- Longhorn Rumors: What's true and what isn't — WinWorld
- Document Preview : General Windows Support
- Retro: Windows Longhorn - Nerdshack
- Code name: Longhorn by John Clyman, PC Mag article
- Microsoft Shows New Features of Windows Longhorn (PCWorld article from 5 May 2004 about WinHEC 2004)
- Indigo: The Longhorn Communications Layer (Figure 1)