AI-FirstResults-DrivenDigital & AI Agency 9800 Richmond Ave, Houston, TX 77042 Start Your Brief

Glossary · Web & App Development

.NET

Definition: .NET is a free, open-source developer platform from Microsoft for building many kinds of applications, including web, mobile, desktop, cloud, and APIs. It runs on Windows, macOS, and Linux and supports the C#, F#, and Visual Basic languages. Modern .NET, formerly .NET Core, is the cross-platform successor to the older Windows-only .NET Framework.

Official source: .NET

Overview

What .NET is

.NET is Microsoft's platform for building and running applications across web, cloud, mobile, desktop, gaming, and IoT. It is free and open source, maintained by Microsoft and the community on GitHub.

The platform combines a runtime, a large standard library, and languages, so developers can share code and skills across very different app types. C# is by far the most widely used .NET language, alongside F# and Visual Basic.

How .NET works

Code compiles to an intermediate language that the runtime (the CLR) executes, handling memory management and just-in-time compilation. The Base Class Library and NuGet packages provide reusable functionality, and frameworks such as ASP.NET Core for web and APIs, MAUI for cross-platform apps, and Blazor for web UI build on top.

Modern .NET, which unified under a single product starting with .NET 5, runs on Windows, macOS, and Linux and is a common target for containers and cloud platforms like Microsoft Azure. Microsoft ships a major version each November, with long-term support releases maintained for three years.

Why .NET matters

.NET is a strong choice for performant, large-scale backends, enterprise systems, and SaaS products, with mature tooling in Visual Studio and a big ecosystem of libraries. Its cross-platform, containerized runtime makes it well suited to modern cloud deployment.

It is worth distinguishing modern .NET from the legacy .NET Framework, which is Windows-only and now in maintenance rather than active feature development. New projects should use modern .NET, while older Framework apps are common candidates for modernization.

FAQ

.NET — common questions

Is .NET free and open source?

Yes. .NET is free to use and open source under the MIT license, maintained by Microsoft and the community on GitHub. There is no fee to build or run applications on it.

What is the difference between .NET and .NET Framework?

Modern .NET (formerly .NET Core) is cross-platform, open source, and actively developed. The older .NET Framework runs only on Windows and is now in maintenance, so new projects should use modern .NET.

What programming language does .NET use?

.NET supports C#, F#, and Visual Basic. C# is the most popular by a wide margin and is used for most web, cloud, mobile, and desktop development on the platform.

Need .NET done right?

Book a free consultation and we’ll map the fastest, most cost-effective path for your project.

Book a free consultation