C# ranks among the top five languages used by GitHub projects, and hundreds of thousands of companies apply it across media, finance, healthcare, and gaming. Its C-family syntax lets JavaScript, Java, and C++ developers adopt it quickly.

The Roslyn compiler platform exposes the compiler's code model as public APIs, enabling analyzers, code fixes, and source generators. Features such as generics, pattern matching, async/await, records, and first-class span support have arrived through the annual release cadence.

Microsoft first distributed C# in July 2000 as part of its .NET Framework initiative, and version 1.0 shipped with Visual Studio .NET in January 2002. Anders Hejlsberg led the language's design together with Scott Wiltamuth and Peter Golde.

Ecma International standardized the language as ECMA-334 with a first edition in December 2001. Microsoft open-sourced the Roslyn compiler platform in 2014, and the project sits under the .NET Foundation with development on GitHub.

C# 15 is in preview and is scheduled to ship with .NET 11 in November 2026, a standard-term-support release backed by two years of support. The .NET Conf 2026 event in November marks the launch.

The C# 15 preview begins a multi-release redesign of the language's memory-safety model that Microsoft expects to keep evolving across the .NET 12 and C# 16 horizon.

C# is a strongly typed, object-oriented programming language that Microsoft maintains for the .NET platform. It is open source and cross-platform, and Microsoft ships a new major version each year alongside the annual .NET release.

The current stable release is C# 14, supported on .NET 10, while C# 15 is in preview on .NET 11 previews. Developers apply the language to web, mobile, desktop, cloud, game, IoT, and machine-learning workloads.