|Microsoft Windows Neptune|
|Kernel version||NT 5.50|
|Release date||Canceled; never released|
|Support end||Canceled; never supported|
|Preceded by||Windows 2000 / Windows ME|
|Succeeded by||Windows XP|
Microsoft Windows "Neptune" (internally at Microsoft also known as NepTune) was planned to become the successor of the Windows 2000 family as well as the first consumer version of Windows under the NT kernel. It was under development in 1999, until it was canceled, along with Odyssey to give way for Whistler, which would be released as Windows XP in 2001. XP included a new login screen, help center and user accounts panel originally envisioned for Neptune. However, Activity Centers were eventually dropped. As stated in confidential Microsoft documents, Neptune was to be released in Q1 2000, planned to have 64-bit edition (referred to as "NT64") for the upcoming Intel Itanium processor, "Solar Coaster" (Unix Services for NT), Internet Explorer 6 (which was also in development at the time) and some Anti-Piracy features. There is evidence that five service packs were planned for Neptune.
A successor called "Triton" was mistaken as a service pack, but as shown in Antitrust documents, it was actually a successor to Neptune which would bring minor updates and enhancements.
The following planned release dates come from PX07297.
- RTM: March 2000
- SP1: May 2000
- SP2: September 2000
- SP3: January 2001
- SP4: July 2001
- SP5: March 2002
Other Neptune SKUs
Microsoft Anti-trust documents from Neptune era indicate that Neptune was to have not only one, but several editions, namely "Entry-Level", "Standard" and "High-End", which could translate into these modern SKUs: "Starter", "Home" and "Professional / Server". It is unknown what these editions would actually become, if Neptune was ever released.
There are also several strings in file USETUP.EXE from Neptune build 5111.1 that clearly mention "Neptune Server". These references could be leftovers from Windows 2000, if all "2000" strings were simply replaced with "Neptune" during the rebranding process.
NOTE: Only Build 5.5.5111.1 was ever leaked, the rest of the builds were mentioned in file versions in various Windows Me builds and Builds 5.5.5118.1, 5.5.5119.1, and 5.5.5120.1 were mentioned in early Windows XP builds.
- No information available
- Existence doubtful
- Information or pictures available
- Leaked or released
- 5.5.5111.1 - Neptune Developer Release and M2 build
- neptune and 2k
- About ME, Neptune Betas
- Neptune, Odyssey, and... Asteroid???
- Windows Neptune Build Leaks
- WinInfo Short Takes: Week of December 13, "SOMEONE SENT AROUND a rumor that Microsoft had sent out non-disclosure agreements (NDAs) for Neptune, the Windows 2000-based Consumer Windows that will follow Millennium. Based on what I've been able to verify personally, this is not true."
- WinInfo Short Takes: Week of January 24, "MICROSOFT HAS CANCELLED the previously separate "Neptune" and "Odyssey" projects, melding the two into a cohesive strategy for the future of Windows 2000."
- In-depth analysis: Future of Windows still in flux, "I received a lot of feedback from my mention in 'Short Takes' about the cancellation of Neptune and Odyssey in lieu of a combined project dubbed "Whistler.""
- WinInfo Short Takes: Week of January 31, "THE INTERNET EXPLORER-related "Mars" project has been postponed by Microsoft Corporation for reasons unknown, but insiders suggest that this is related to the recent merging of "Neptune" and "Odyssey" into "Whistler," the next version of Windows 2000."
- SuperSite Flashback: Neptune
- Before Slack and Teams: The Windows Service (1998), "In 1998, I was working on the “RedShark” project to create a new user interface, along with Joe Belfiore, Steve Capps, and a team of ~15 other Microsoft employees. We imagined this could become a “software as a service” called “Neptune” that would supersede Windows. [Obviously, that did not happen…]" - Contains a presentation on "The Windows Service" with a Startpage. (Referenced on Brad Silverberg 🇺🇦 (@bradsilverberg) (29 March 2021). Ben Slivka @BenSlivka posted his Neptune presentation from August 1998. It’s brilliant but just too far ahead of its time for Microsoft then. Ben has a series of brilliant memos from the mid 90’s.. Twitter. Retrieved on 17 April 2022.</ref>