Swift 6.4 makes the Swift Build system the default build engine for Swift Package Manager, streamlining compilation across platforms. The unified approach works seamlessly in Apple's Xcode IDE, from the command line, and now directly in VS Code—removing friction for developers working across different environments.
Beyond build improvements, the release strengthens interoperability with C++, Java, JavaScript, and WebAssembly. These additions broaden Swift's reach beyond Apple's ecosystem, making it more practical for cross-platform and polyglot development workflows.