add supported versions page (#8242)

Author: LordSimal

docs/en/intro.md

@@ -137,13 +137,13 @@ following steps:
 2. Your Application is loaded and bound to an `HttpServer`.
 3. Your application's middleware is initialized.
 4. A request and response is dispatched through the PSR-7 Middleware that your
-    application uses. Typically this includes error trapping and routing.
+   application uses. Typically this includes error trapping and routing.
 5. If no response is returned from the middleware and the request contains
-    routing information, a controller & action are selected.
+   routing information, a controller & action are selected.
 6. The controller's action is called and the controller interacts with the
-    required Models and Components.
+   required Models and Components.
 7. The controller delegates response creation to the View to generate the output
-    resulting from the model data.
+   resulting from the model data.
 8. The view uses Helpers and Cells to generate the response body and headers.
 9. The response is sent back out through the [Middleware](controllers/middleware).
 10. The `HttpServer` emits the response to the webserver.

docs/en/intro/supported-versions.md

@@ -0,0 +1,49 @@
+# Semantic Versioning
+
+See [CakePHP Development Process](../appendices/cakephp-development-process.md) and the [Backwards Compatibility Guide](../contributing/backwards-compatibility)
+
+## CakePHP Supported Versions
+
+This table was last updated in February 2026.
+
+| Major Version | Supported Version | PHP-Version    | Active Support | Security Support     |
+|---------------|-------------------|----------------|----------------|----------------------|
+| `5.x`         | `5.1` to `5.3`    | `8.1` to `8.5` | `5.3+`         | ✅                    |
+| `4.x`         | `4.4` to `4.6`    | `7.2` to `8.3` | ❌              | September 10th, 2026 |
+| `3.x`         | None              | `5.6` to `7.4` | ❌              | ❌                    |
+| `2.x`         | None              | `5.4` to `7.4` | ❌              | ❌                    |
+| `1.x`         | None              | `¯\_(ツ)_/¯`    | ❌              | ❌                    |
+
+### Major Version Support
+
+We follow the rule to support the previous major version for
+
+- 24 months of `active support` (includes new features and bugfixes) and
+- 36 months of `security support`
+
+after the release of a new major version.
+
+E.g. [CakePHP 5.0](https://github.com/cakephp/cakephp/releases/tag/5.0.0) released on September 10th 2023,
+so we will support CakePHP 4.x until September 10th 2025 and provide security updates until September 10th 2026.
+
+### Minor Version Support
+
+`Active support` for a minor branch ends the moment a new minor branch is released.
+E.g. when CakePHP 5.2 is released, active support for CakePHP 5.1 will end and only security updates will be provided.
+
+`Security updates` will be provided
+
+- till the end of the support period for the major version, or
+- 3 new minor releases have been published (e.g. `5.2` support ended when `5.5` was released)
+
+whichever comes first.
+
+> [!TIP]
+> Keep production applications on a currently supported major line and plan
+> regular upgrades to stay within supported minor ranges.
+
+> [!TIP]
+> Each minor and major release of CakePHP includes automated upgrade commands which you
+> can use to upgrade your application or plugin. See e.g. the
+> [upgrade guide](../appendices/5-0-upgrade-guide.md#use-the-upgrade-tool)
+> for more details on how to use these commands.

toc_en.json

@@ -8,6 +8,10 @@
         { "text": "Installation", "link": "/installation" },
         { "text": "Introduction", "link": "/intro" },
         { "text": "Structure & Conventions", "link": "/intro/conventions" },
+        {
+          "text": "Supported Versions",
+          "link": "/intro/supported-versions"
+        },
         {
           "text": "Where to Get Help",
           "link": "/intro/where-to-get-help"