Yii Framework

Yii is a high-performance PHP framework, best for developing Web 2.0 applications. Yii is a generic Web programming framework, meaning that it can be used for developing all kinds of Web applications using PHP. Because of its component-based architecture and sophisticated caching support, it is especially suitable for developing large-scale applications such as portals, forums, content management systems (CMS), e-commerce projects, Restful Web services, and so on.

Why Yii?

Yii is a free, open-source framework for PHP5 that promotes clean, DRY design, and supports rapid development.
Yii offers the breadth of everything we expect from a framework in a high performance package with few of the limitations other PHP frameworks inflict.
Yii’s stands out for its performance, which is critical when you adopt a framework:
The Yii framework also offers a breadth of capabilities that allow me to quickly and easily write optimized web applications.
Yii offers excellent documentation and a supportive community.
Yii is mature, time-tested and stable.

Yii History

The Yii project started on January 1, 2008, in order to fix some drawbacks of the PRADO framework. For example, in its early versions PRADO was slow when handling complex pages had a steep learning curve and many controls were difficult to customize, while Yii was much more efficient at that time. In October 2008, after ten months of private development, the first alpha version of Yii was released. On December 3, 2008, Yii 1.0 was formally released.

Yii Versions:

Currently Yii has two major versions available: 1.1 and 2.0.
Version 1.1 is the old generation.
Version 2.0 is a complete rewrite of Yii,
Yii 2.0 requires PHP 5.4.0 or above.

Yii features include

Model-View-Controller architecture.
Database Access Objects, Active Record, and programmatic Database migrations simplify the challenges of building database-powered web applications.
Yii makes forms pretty easy Form input, validation and Ajax support which is built-in…
Built-in authentication and powerful user management extensions make launching new web applications easy.
Yii’s built-in code generation tool, Gii, speeds your app’s development scaffolding in MVC fashion.
Console Yii. You can run Yii from the command line or as a daemon. With this, it’s possible to build high performance background tasks in PHP.
Theming options such as the Bootstrap extension makes building great looking responsive apps much simpler.
Layered caching support Yii makes it easy to implement the kinds of caching that make sense to your application.
Integration with other frameworks. It’s easy to use Send or PEAR features in Yii.
Extensions. Yii’s community offers a variety of free, open source plugging and widgets.
Internationalization. Yii supports I18N and makes it easy to provide localized versions of your app.
Error handling, logging and testing – yes, Yii delivers.
Fast. Yii only loads the features that you need. It has powerful caching support. It is explicitly designed to work efficiently with AJAX.
Secure. Security comes as standard with Yii. It includes input validation, output filtering, SQL injection and Cross-site scripting prevention.
Professional. Yii helps you develop clean and reusable code. It follows the MVC pattern, ensuring a clear separation of logic and presentation.