This is a post in a similar bent to yesterday’s post, “Why wasn’t there Windows 9”

The reason is even more straightforward.

The .NET Framework, first launched in 2002, has the following releases:

  • 1
  • 1.1
  • 2
  • 3
  • 3.5
  • 4.0
  • 4.5
  • 4.5.1
  • 4.5.2
  • 4.6
  • 4.6.1
  • 4.6.2
  • 4.7
  • 4.7.1
  • 4.7.2
  • 4.8
  • 4.8.1

This was a Windows-only affair.

In 2016, a pivotal change came about: the .NET Framework was rewritten to be cross-platform, with a new name: .NET Core.

These were the releases:

  • .NET Core 1.0
  • .NET Core 1.1
  • .NET Core 2.0
  • .NET Core 2.1
  • .NET Core 2.2
  • .NET Core 3.0
  • .NET Core 3.1
  • .NET 5
  • .NET 6
  • .NET 7
  • .NET 8
  • .NET 9
  • .NET 10

A couple of things to note:

  1. There is no .NET 4
  2. The name changed from .NET Core to .NET from version 5

The reason for this is pretty simple - it would have been a nightmare for developers and users to have both a .NET Framework 4 and a .NET Core 4. Think web searches, documentation, blogs, StackOverflow.

Omitting .NET Core 4 and going to 5 neatly sidestepped this problem.

You might be asking what is special about .NET 4, given that the same problem would exist for prior versions.

The reason is that .NET Framework 4 is still actively supported, and many current applications still run on those versions.

To be specific, these are the versions under active support:

Version Release date
.NET Framework 4.8.1 August 9, 2022
.NET Framework 4.8 April 18, 2019
.NET Framework 4.7.2 April 30, 2018
.NET Framework 4.7.1 October 17, 2017
.NET Framework 4.7 April 5, 2017
.NET Framework 4.6.2 August 2, 2016

TLDR

There is no .NET Core 5 because it would massively confuse developers and users.

Happy hacking!