Thank you for choosing Yii 2 - a modern PHP framework designed for professional Web development.

Yii 2 is a complete rewrite of its previous version Yii 1.1 which is one of the most popular PHP frameworks. Yii 2 inherits the main spirit behind Yii for being simple, fast and highly extensible. Yii 2 requires PHP 5.4 and embraces the best practices and protocols found in modern Web application development.

Yii 2 is not ready for production use yet. We may make significant changes without prior notices. We expect to make the first stable release of Yii 2 in the middle of 2014.

If you mainly want to learn Yii with no real project development requirement, we highly recommend you start with Yii 2 as it will be our main focus for the next few years.

If you have a real project with tight schedule, you should stick to Yii 1.1 which is the latest stable release of Yii.

apps/                ready-to-use application templates
    advanced/        a template suitable for building sophisticated Web applications
    basic/           a template suitable for building simple Web applications
    benchmark/       an application demonstrating the performance of Yii
build/               internally used build tools
docs/                documentation
extensions/          extensions
framework/           core framework code
tests/               tests of the core framework code

The minimum requirement by Yii is that your Web server supports PHP 5.4.

A draft of the Definitive Guide is available.

API docs and a rendering of the definitive guide are currently available under the following urls:

• http://www.yiiframework.com/doc-2.0/ API and Definitive Guide (updated daily)
• http://stuff.cebe.cc/yii2docs/ API and Definitive Guide (updated every 15 minutes)
• http://stuff.cebe.cc/yii2-guide.pdf The PDF version of the Guide

For 1.1 users, you may refer to Upgrading from Yii 1.1 to have a general idea of what has changed in 2.0.

Your participation to Yii 2 development is very welcome!

You may participate in the following ways:

• Report issues
• Give us feedback or start a design discussion
• Fix issues, develop features, write/polish documentation
  • Before you start, please adopt an existing issue (labelled with "ready for adoption") or start a new one to avoid duplicated efforts.
  • Please submit a merge request after you finish development.

In order to make it easier we've prepared special yii2-dev Composer package.