Add a shared platform support pattern to Apple platforms, Linux, and Windows

apple-platforms/Sources/SwiftApplePlatforms.docc/Documentation.md

@@ -7,9 +7,37 @@ Build and ship apps for iOS, iPadOS, macOS, watchOS, tvOS, and visionOS.
     @TitleHeading("")
 }
 
+## Overview
+
 Swift is the primary language for building apps across Apple's platforms, with
 deep integration into Xcode, Apple's SDKs, and frameworks like SwiftUI and
 UIKit.
 
 Visit [Apple Developer Documentation](https://developer.apple.com/documentation/technologies)
 for platform-specific APIs, frameworks, and guides.
+
+### Platform support
+
+Apple platforms are a **Tier 1** platform under
+[SP-0001, Swift Platform Support Tiers](https://github.com/swiftlang/swift-evolution/blob/main/policies/0001-platform-support-tiers.md).
+macOS is a toolchain host — you develop with Swift on macOS and deploy to
+macOS itself, or to iOS, watchOS, and tvOS.
+
+| Platform | Deployment | Minimum version |
+|---|---|---|
+| macOS | Development and deployment | 10.13 |
+| iOS | Deployment only | 11.0 |
+| watchOS | Deployment only | 4.0 |
+| tvOS | Deployment only | 11.0 |
+
+On macOS, Swift Package Manager, SourceKit-LSP, the LLDB debugger, and the
+Swift REPL are all available. On iOS, watchOS, and tvOS, only the debugger
+applies, since apps for those platforms are built on macOS rather than on
+the device itself.
+
+Apple Inc. owns support for Apple platforms and requires pull request
+testing to pass before merging changes that affect them. See
+[Install Swift on macOS](https://www.swift.org/getting-started/#on-macos) to
+get started, or the full
+[platform support matrix](https://www.swift.org/platform-support/) for how
+Apple platforms compare with every other platform Swift supports.

linux/Sources/SwiftLinux.docc/Documentation.md

@@ -7,6 +7,33 @@ Build and host libraries, apps, and services on Linux.
     @TitleHeading("")
 }
 
+## Overview
+
+Linux is a **Tier 1** platform under
+[SP-0001, Swift Platform Support Tiers](https://github.com/swiftlang/swift-evolution/blob/main/policies/0001-platform-support-tiers.md).
+The Swift project provides official toolchain builds, so you can both
+develop and deploy Swift on Linux.
+
+### Platform support
+
+| Distribution | Minimum version |
+|---|---|
+| Ubuntu | 22.04 |
+| Debian | 12 |
+| Fedora | 41 |
+| Amazon Linux | 2023 |
+| Red Hat Universal Base Image | 9 |
+
+Every supported distribution includes the same set of tools: Swift Package
+Manager, SourceKit-LSP, the LLDB debugger, and the Swift REPL.
+
+Apple Inc. owns support for Linux and requires pull request testing to pass
+before merging changes that affect it. See
+[Install Swift on Linux](https://www.swift.org/getting-started/#on-linux) to
+get started, or the full
+[platform support matrix](https://www.swift.org/platform-support/) for how
+Linux compares with every other platform Swift supports.
+
 ## Topics
 
 - <doc:ServerGuides>

windows/Sources/SwiftWindows.docc/Documentation.md

@@ -7,9 +7,28 @@ Build and run Swift on Windows.
     @TitleHeading("")
 }
 
+## Overview
+
 Swift supports native development on Windows, including a downloadable
 toolchain and integration with Visual Studio's build tools.
 
 Visit [Install Swift on Windows](https://www.swift.org/install/windows/) to
 get started. More guidance on building and porting packages to Windows is
 coming soon.
+
+### Platform support
+
+Windows is a **Tier 1** platform under
+[SP-0001, Swift Platform Support Tiers](https://github.com/swiftlang/swift-evolution/blob/main/policies/0001-platform-support-tiers.md),
+and a toolchain host — the Swift compiler, Swift Package Manager, and
+SourceKit-LSP all run natively on Windows 10.0 and later.
+
+The LLDB debugger is available on Windows, but the Swift REPL isn't
+currently supported there.
+
+Apple Inc. owns support for Windows and requires pull request testing to
+pass before merging changes that affect it. See
+[Install Swift on Windows](https://www.swift.org/getting-started/#on-windows)
+to get started, or the full
+[platform support matrix](https://www.swift.org/platform-support/) for how
+Windows compares with every other platform Swift supports.