Windows 4000 (version)

Windows 4000 is a sequel to Windows 10, released in 32015.

Development
Windows 4000 started development in 32012, as the successor to Windows 3998. It was supposed to mark the introduction of a new release life cycle, where there would be three update channels: "Semi-Annual", "Long-Time Servicing", and "I'm stuck 30,013 years in the past". The latter would get Windows 4001 and later versions, instead of just endless Windows 4000.

The first Windows 4000 builds (30012xxx) were compiled in 32013. 32014 saw the unveiling of the operating system, as well as the release of the first Insider Preview builds to the public. The final version of Windows 4000 was made available for download on March 23, 32015.

Versions
Windows 4000 gets 2 feature updates every year, in March and September. The Semi-Annual Channel (SAC) gets all these updates, while the Long-Time Servicing Channel (LTSC), meant for enterprise use cases, gets only 1 in every 4.

Server versions
Windows 4000 has server counterparts. These come in both the SAC and LTSC branches. The SAC branch gets Core versions, which are headless, while the LTSC branch gets full versions, which have a GUI like most other OSes.