diff --git a/extensions/composer/Installer.php b/extensions/composer/Installer.php
index 0dda073..3a77671 100644
--- a/extensions/composer/Installer.php
+++ b/extensions/composer/Installer.php
@@ -85,13 +85,13 @@ class Installer extends LibraryInstaller
 
 	protected function loadExtensions()
 	{
-		$file = $this->vendorDir . '/yii-extensions.php';
+		$file = $this->vendorDir . '/yiisoft/extensions.php';
 		return is_file($file) ? require($file) : [];
 	}
 
 	protected function saveExtensions(array $extensions)
 	{
-		$file = $this->vendorDir . '/yii-extensions.php';
+		$file = $this->vendorDir . '/yiisoft/extensions.php';
 		file_put_contents($file, "<?php\nreturn " . var_export($extensions, true) . ";\n");
 	}
 
diff --git a/extensions/composer/README.md b/extensions/composer/README.md
index 853d3c3..1f06083 100644
--- a/extensions/composer/README.md
+++ b/extensions/composer/README.md
@@ -1,44 +1,65 @@
-Yii 2.0 Public Preview - Composer Installer
-===========================================
-
-Thank you for choosing Yii - a high-performance component-based PHP framework.
-
-If you are looking for a production-ready PHP framework, please use
-[Yii v1.1](https://github.com/yiisoft/yii).
-
-Yii 2.0 is still under heavy development. We may make significant changes
-without prior notices. **Yii 2.0 is not ready for production use yet.**
+Yii 2 Composer Installer
+========================
 
 [![Build Status](https://secure.travis-ci.org/yiisoft/yii2.png)](http://travis-ci.org/yiisoft/yii2)
 
-This is the yii2 composer installer.
+This is the composer installer for Yii 2 extensions. It implements a new composer package type named `yii2-extension`,
+which should be used by all Yii 2 extensions if they are distributed as composer packages.
 
 
-Installation
-------------
+Usage
+-----
 
-This extension offers you enhanced Composer handling for your yii2-project. It will therefore require you to use Composer.
+To use Yii 2 composer installer, simply set `type` to be `yii2-extension` in your `composer.json`,
+like the following:
 
+```json
+{
+	"type": "yii2-extension",
+	"require": {
+		"yiisoft/yii2": "*"
+	},
+	...
+}
 ```
-php composer.phar require yiisoft/yii2-composer "*"
-```
-
-*Note: You might have to run `php composer.phar selfupdate` before using this extension.*
-
-
-Usage & Documentation
----------------------
 
-This extension allows you to hook to certain composer events and automate preparing your Yii2 application for further usage.
-
-After the package is installed, the `composer.json` file has to be modified to enable this extension.
-
-To see it in action take a look at the example apps in the repository:
-
-- [Basic](https://github.com/suralc/yii2/blob/master/apps/basic/composer.json#L27)
-- [Advanced](https://github.com/suralc/yii2/blob/extensions-readme/apps/advanced/composer.json)
-
-However it might be useful to read through the official composer [documentation](http://getcomposer.org/doc/articles/scripts.md)
-to understand what this extension can do for you and what it can't.
+You may specify a bootstrap class in the `extra` section. The class will be executed each time
+the Yii 2 application is responding to a request. For example,
+
+```json
+{
+	"type": "yii2-extension",
+	...,
+	"extra": {
+		"bootstrap": "yii\\jui\\Extension"
+	}
+}
+```
 
-You can also use this as a template to create your own composer additions to ease development and deployment of your app.
+The `Installer` class also implements a static method `setPermission()` that can be called after
+a Yii 2 projected is installed, through the `post-create-project-cmd` composer script.
+The method will set specified directories or files to be writable or executable, depending on
+the corresponding parameters set in the `extra` section of the `composer.json` file.
+For example,
+
+```json
+{
+	"name": "yiisoft/yii2-app-basic",
+	"type": "project",
+	...
+	"scripts": {
+		"post-create-project-cmd": [
+			"yii\\composer\\Installer::setPermission"
+		]
+	},
+	"extra": {
+		"writable": [
+			"runtime",
+			"web/assets"
+		],
+		"executable": [
+			"yii"
+		]
+	}
+}
+```