Stage 1 · Lesson 1 of 7

What .NET is, and which version to use

Modern .NET is a free, open source, cross-platform runtime and set of libraries from Microsoft. It runs on Windows, Linux and macOS. It is not the old .NET Framework, which is Windows only and in maintenance; many banks still run Framework apps, but new work is on modern .NET.

A new version ships every November. Even numbers are LTS (, 3 years) and odd numbers are STS (standard term support, 2 years). As of October 2026, .NET 10 is the current LTS, supported until November 2028. .NET 8 and .NET 9 both end support on 10 November 2026, and .NET 11 is due that month. Enterprise teams usually stay on LTS.

Common traplearning from a 2019 tutorial that uses Startup.cs and .NET Core 3.1, then being confused by every modern project.

A question to check yourself, an AI practice session and 1 cheat sheet entry come with the full roadmap. Unlock

Resources for this stage

Start with· follow one of these

GuideFree
Learn C#
Microsoft · Beginner
Free official C# path: syntax, types, classes, collections and exceptions with in-browser exercises
GuideFree
.NET documentation
Microsoft
The official .NET docs: start with the CLI overview, project files and the C# language tour

Practise

Exercism
The free C# track: small exercises with mentor feedback that build fluency fast

Keep handy

DevDocs
Searchable offline docs, handy for C# and .NET API lookups while you practise

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