dotnet/runtime

This repository is the source code for the .NET Runtime, the core engine that makes .NET applications run. .NET is a software platform from Microsoft that lets developers build and run applications on many different kinds of hardware and operating systems, including cloud servers, mobile devices, desktop computers, and IoT (Internet of Things) devices. It is written primarily in C#. What this specific repository contains is the lowest-level infrastructure: the runtime itself (which executes your .NET code), the base class libraries (the built-in code that .NET programs can call, things like file handling, networking, data structures, and string operations), and the tools used to install and run .NET on a machine. This is not a library you import into a project; it is the underlying system that your .NET programs run on top of. Because this is such a fundamental piece of software, it is extremely large and complex, and contributing to it requires following detailed workflow instructions about how to build and test changes. The repository includes guidance for contributors, links to documentation, and instructions for getting nightly builds if you want to test unreleased changes in your own projects. You would browse or contribute to this repository if you are a developer working on the .NET platform itself, for example, fixing bugs in the runtime, improving performance of the base libraries, or adding new language features. Most .NET application developers never need to look here; they just use .NET through its official installer and tools. The project is open source under the MIT license and governed by the .NET Foundation.