BetaWiki:Featured article/2020-02
Windows Neptune build 5111.1 is a build of Windows Neptune. As of 2020, it is the only leaked build of Windows Neptune. It's also known as "Microsoft Neptune Developer Release" and was sent to developers on 1999-12-27. Much of the branding (including Winver) still says "Windows 2000". Although many files have the version "5.50.5111.1", and this is even the true version in the kernel, the kernel actually reports "5.00.5111.1" to match the subsystem version in its own PE header.
It includes the Activity Centers, a new login interface and user management application, an early version of Internet Explorer 5.5, as well as the new Help Center and AutoUpdate from Windows ME and several other improvements. It's configured to hibernate rather than shut down by default.