diff --git a/README.md b/README.md
new file mode 100644
index 0000000..137868b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,34 @@
+# No trailing comma
+
+Placeholder package for clean diffs in JSON package definition files.
+
+## Usage
+
+### Composer
+
+1. Configure root project to automatically sort packages.
+  ```sh
+  $ composer config sort-packages true
+  ```
+  ```json
+  "config": {
+    "sort-packages": true
+  }
+  ```
+
+1. Install this package as dependency.
+  ```sh
+  $ composer require zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz/no-trailing-comma
+  $ composer require --dev zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz/no-trailing-comma
+  ```
+
+### npm
+
+1. Install this package as dependency.
+  ```sh
+  $ npm install zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz-no-trailing-comma
+  $ npm install --save-dev zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz-no-trailing-comma
+  ```
+
+Notes
+* npm sorts packages alphabetically whenever you invoke the commands `install` and `remove`. You can pass the  name of a non-existing package to them to manually sort dependencies in `package.json` once.
diff --git a/composer.json b/composer.json
index 1cca7d9..bdb0020 100644
--- a/composer.json
+++ b/composer.json
@@ -10,5 +10,8 @@
         }
     ],
     "minimum-stability": "dev",
-    "require": {}
+    "require": {},
+    "config": {
+        "sort-packages": true
+    }
 }
diff --git a/index.js b/index.js
new file mode 100644
index 0000000..e69de29
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..a2708da
--- /dev/null
+++ b/package.json
@@ -0,0 +1,20 @@
+{
+  "name": "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz-no-trailing-comma",
+  "version": "1.1.0",
+  "description": "Placeholder package for clean diffs in package.json.",
+  "keywords": ["npm", "package", "json", "package.json", "diff", "dev", "development"],
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz/no-trailing-comma.git"
+  },
+  "author": "Daniel Kudwien <sun@netzstrategen.com> (https://netzstrategen.com)",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz/no-trailing-comma/issues"
+  },
+  "homepage": "https://github.com/zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz/no-trailing-comma"
+}