|Version of Microsoft Windows|
|OS family||Windows NT|
The Longhorn project was intended as a bridging release between Whistler and the later version of Windows codenamed Blackcomb, which much later became Windows 7. Over time, many features slated for Blackcomb became part of Longhorn, and employees jumped ship from other parts of the company. Longhorn became a bloated, unstable piece of vaporware. The first build to leak publicly was build 3683, which contained a new theme, and also the foundations for WinFS, and Avalon, which eventually became the Windows Presentation Framework. "Longhorn" was originally intended to be an interim release, but picked up many features slated for its successor.
Stability increasingly became an issue as development progressed, and few builds were publicly released as a result (including the lack of Home Edition builds). In fact, the only build to become officially available from Microsoft to the wider world was build 4074[source?]. The last known confirmed build from before the development reset is build 4093. After the compilation of build 4093, the development of Longhorn was reset, mainly because of the instability of the current Longhorn branch. At about 9 PM, on the same day as the compilation of 4093, Microsoft stopped development of Windows Longhorn and started fresh using Windows Server 2003 Service Pack 1 as a codebase, starting the Omega-13 period. Immediate post-reset builds have been primarily focused on reintegrating features from the pre-reset builds while maintaining stability. Most of these builds are similar to Windows XP in overall look and feel. Few builds from this stage of development have been released, officially or otherwise. Development of Longhorn continued, albeit many features originally slated for inclusion were delayed or dropped to provide a more realistic operating system. Examples of this include WinFS, and what would become Windows PowerShell.
In April 2005, a pre-beta build was released to testers (build 5048). This build showed the progress made since the reset and also proved much more stable than previous builds. Build 5112 (Beta 1) was released to the public soon afterward and showcased an early version of the Aero interface, as well as many stability improvements over XP. Over the next year, many builds were pushed to testers in a public beta program. The final build out to public preview testers was Release Candidate 2 (build 5744). The RTM build was build 6000.16386.
Windows Vista came in many editions. Unlike Windows XP, there was no special edition for Media Center and 64-bit capability, since these features were included in at least one of the consumer editions. Windows Vista also did not have an embedded version, perhaps due to the considerable grunt required to run optimally.
- Starter: This edition is intended for emerging markets and low-cost PCs. As in XP, the 3-program limit was there, and only 1GB RAM was accepted. Other software restrictions applied as well. This version is hence not available in 64-bit.
- Home Basic: Found in low cost to mid-end, this version of Windows Vista does not fully have Aero (though it has DWM) and hence does not have effects like transparency and 3D Flip. Windows Media Center is also dropped from this build. Parental Controls is included, however. It does not have the hardware and 3-program limit.
- Home Premium: The consumer version of Windows Vista, this version includes full Aero functionality and Windows Media Center. It also includes Premium Games (eg - Inkball).
- Business: The business-oriented version of Windows Vista, it contains several features like full RDP (client/host) capability, Group Policy, and domain joinability. However, Windows Media Center and Parental Controls are not included, and Premium Games are disabled by default.
- Ultimate: The top consumer variant of Windows Vista, it is a merger of the features included Windows Vista Home Premium and Business. BitLocker is included in this version.
- Enterprise: The business variant of Windows Vista. It is similar to Ultimate, but without Windows Media Center and includes enterprise-specific tools.