Add JHarmonizer into the README as a third-party integration

README.md

@@ -14,6 +14,7 @@ _A modern, lambda-friendly, 120 character Java formatter._
 - [IntelliJ plugin](https://plugins.jetbrains.com/plugin/13180-palantir-java-format)
 - [Gradle plugin](#palantir-java-format-gradle-plugin)
 - [Spotless](#spotless)
+- [JHarmonizer](#jharmonizer)
 
 It is based on the excellent [google-java-format](https://github.com/google/google-java-format), and benefits from the work of all the [original authors](https://github.com/google/google-java-format/graphs/contributors). palantir-java-format is available under the same [Apache 2.0 License](./LICENSE).
 
@@ -150,6 +151,30 @@ when formatting java code.
 - See [integration in Spotless Gradle plugin](https://github.com/diffplug/spotless/tree/main/plugin-gradle#palantir-java-format).
 - See [integration in Spotless Maven plugin](https://github.com/diffplug/spotless/tree/main/plugin-maven#palantir-java-format).
 
+## JHarmonizer
+
+> This is a community-maintained third-party tool and is not officially supported by Palantir Technologies.
+
+[JHarmonizer](https://github.com/lemon-ant/JHarmonizer) sorts and formats
+Java source files. It reorders class members — fields, constructors,
+methods, nested types, and initializer blocks — according to configurable
+rules, then formats the result using `palantir-java-format`. Before
+reordering, JHarmonizer analyses the relationships between class members
+(for example, which fields are read by which initializers) to ensure the
+reordered source still compiles and behaves correctly.
+
+JHarmonizer works in two modes:
+
+- **Reorder and format** – automatically reorder and format sources during the build or from the command line.
+- **Check** – verify that sources are already correctly ordered and formatted; fail the build (or report all violations) if they are not. Useful for enforcing standards in CI.
+
+It is available as:
+
+- **CLI tool** – a standalone fat JAR for use outside of Maven; sort and format Java source files directly from the command line.
+- **Maven plugin** – a build-lifecycle plugin that binds reordering and checking goals to standard Maven phases (`process-sources`, `validate`, etc.).
+
+See the [JHarmonizer repository](https://github.com/lemon-ant/JHarmonizer) for installation instructions and configuration options.
+
 ## IntelliJ plugin
 
 A

changelog/@unreleased/pr-1661.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Add JHarmonizer into the README as a third-party integration
+  links:
+  - https://github.com/palantir/palantir-java-format/pull/1661