Microsoft has 11 featuring C# 15, which introduces union types and closed class hierarchies.

The release includes performance optimizations, a default Native AOT-based CLI host for Linux and macOS, and OpenAPI 3.2 defaults, alongside the end of support 8 and 9.

Faster and lighter applications

The new version focuses on efficiency. .NET 11 includes hundreds of improvements that help applications run faster and require less memory from the computer. For those using Linux and macOS operating systems, the software installations are now smaller in size. In addition, support for the modern Zstandard file compression method has been added, as well as new options for documenting web services through the OpenAPI 3.2 standard.

In the field of web applications, ASP.NET Core 11 now allows for the control of data entered by users in a way that does not "freeze" the application during the process.

Support and upgrades

.NET 11 is a two-year support release.…