Backward Compatibility, Go 1.21, and Go 2

Go 1.21 includes new features to improve compatibility.

Go is focused on backward compatibility and improving compatibility with each new release, but the language also recognizes that making changes can sometimes break programs. Go's approach to maintaining compatibility includes adding new APIs without breaking existing code, using tools to check for compatibility issues, and running tests to identify potential breaking changes. The goal is to minimize disruptions while still making improvements to the language.