What are the correct version numbers for C#?

Question

What are the correct version numbers for C#? What came out when? Why can\'t I find any answers about C# 3.5?

This question is primarily to

Answer 1

This is the same as most answers here, but tabularized for ease, and it has Visual Studio and .NET versions for completeness.

╔════════════╦════════════╦══════════════╦═════════════╦══════════════╗
║ C# version ║ VS version ║ .NET version ║ CLR version ║ Release date ║
╠════════════╬════════════╬══════════════╬═════════════╬══════════════╣
║    1.0     ║    2002    ║    1.0       ║     1.0     ║   Feb 2002   ║
║    1.2     ║    2003    ║    1.1       ║     1.1     ║   Apr 2003   ║
║    2.0     ║    2005    ║    2.0       ║     2.0     ║   Nov 2005   ║
║            ║            ║    3.0       ║     2.0     ║   Nov 2006   ║
║    3.0     ║    2008    ║    3.5       ║     2.0     ║   Nov 2007   ║
║    4.0     ║    2010    ║    4.0       ║     4       ║   Apr 2010   ║
║    5.0     ║    2012    ║    4.5       ║     4       ║   Aug 2012   ║
║    5.0     ║    2013    ║    4.5.1     ║     4       ║   Oct 2013   ║
║            ║            ║    4.5.2     ║     4       ║   May 2014   ║
║    6.0     ║    2015    ║    4.6       ║     4       ║   Jul 2015   ║
║            ║            ║    4.6.1     ║     4       ║   Nov 2015   ║
║            ║            ║    4.6.2     ║     4       ║   Aug 2016   ║
║    7.0     ║    2017    ║              ║             ║   Mar 2017   ║
║            ║            ║    4.7       ║     4       ║   May 2017   ║
║    7.1     ║ 2017(v15.3)║              ║             ║   Aug 2017   ║
║            ║            ║    4.7.1     ║     4       ║   Oct 2017   ║
║    7.2     ║ 2017(v15.5)║              ║             ║   Dec 2017   ║
║            ║            ║    4.7.2     ║     4       ║   Apr 2018   ║
║    7.3     ║ 2017(v15.7)║              ║             ║   May 2018   ║
║    8.0     ║    2019    ║    4.8       ║     4       ║   Apr 2019   ║
║    9.0     ║ 2019(v16.8)║    5.0^      ║     ^^      ║   Nov 2020   ║ 
╚════════════╩════════════╩══════════════╩═════════════╩══════════════╝

^ - .NET 5.0 is not a newer version of .NET framework but .NET Core 3. Starting from .NET 5.0, there are no newer versions of .NET full framework.

^^ - There are no separate CLR (CoreCLR) versions for .NET Core. Whatever is the .NET Core version is the CoreCLR version. So not mentioning it.

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Note: .NET development is pretty much independent of VS these days, there is no correlation between versions of each.
Refer to ".NET Framework versions and dependencies" for more.