With simplicity and efficiency being the priority in mind, several days ago, I discovered Kohana and was impressed. As clearly specified on its homepage, Kohana was originally based on CodeIgniter, so CI users should find no difficulties migrating. Then, along its (community-driven) development way, Kohana has grown quite a bit, and now looks like a very promising PHP framework. Among its features:

• Highly secure
• Extremely lightweight
• Short learning curve
• Uses the MVC pattern
• 100% UTF-8 compatible
• Loosely coupled architecture
• Extremely easy to extend

And the things make it stand out from the crowd:

1. Community, not company, driven. Kohana development is driven by a team of dedicated people that need a framework for fast, powerful solutions.
2. Strict PHP 5 OOP. Offers many benefits: visibility protection, automatic class loading, overloading, interfaces, abstracts, and singletons.
3. Extremely lightweight. Kohana has no dependencies on PECL extensions or PEAR libraries. Large, monolithic libraries are avoided in favor of optimized solutions.
4. GET, POST, COOKIE, and SESSION arrays all work as expected. Kohana does not limit your access to global data, but offers filtering and XSS protection.
5. True auto-loading of classes. True on-demand loading of classes, as they are requested in your application.
6. No namespace conflicts. All classes are suffixed to allow similar names between components, for a more coherent API.
7. Cascading resources offer unparalleled extensibility. Almost every part of Kohana can be overloaded or extended without editing core system files. Modules allow multi-file plugins to be added to your application, transparently.
8. Library drivers and API consistency. Libraries can use different “drivers” to handle different external APIs transparently. For example, multiple session storage options are available (database, cookie, and native), but the same interface is used for all of them. This allows new drivers to be developed for existing libraries, which keeps the API consistent and transparent.
9. Powerful event handler. Observer-style event handlers allow for extreme levels of customization potential.
10. Rapid development cycle. Rapid development results in faster response to user bugs and requests.

You can tell that, originally a fork from CodeIgniter, Kohana should inherit the best from CI when having many improvements. Yes, it’s true. First, it’s PHP 5, so you can take full advantages of the new features available in this version. Second, it doesn’t limit your data in POST and SESSION as CI does (by default, CI disables GET, and it was a nightmare for me trying to integrate Google Custom Search into my CI-based website). Third, it has cool libraries, with the most powerful being ORM, which is a must-have for serious enterprise application.

With this being said, I’ll not dust away CodeIgniter anytime soon. Nevertheless, CI is already mature, with a good userbase, when Kohana is still in its beginning phase and thus has true support limitations. Both have their own pros and cons, so while sticking with CI, I will start playing around with Kohana.

To my readers: please spread the words! Kohana is definitely a very promising PHP framework. By featuring it on your own blog, you’re helping an free, useful, open-source, community-driven application grow. That also is contribution

When the previous version (1.6.3) was just more or less about maintenance and bug fixes, 1.7.0 makes a step further to add many new and enhanced features. To name a few (from the Change Log):

• Added a new Form Validation Class. It simplifies setting rules and field names, supports arrays as field names, allows groups of validation rules to be saved in a config file, and adds some helper functions for use in view files[...] (Me: Perfect. The old validation class was really a failure of CI, as it was ugly and prone to misunderstanding)
• Updated the Sessions class so that any custom data being saved gets stored to a database rather than the session cookie (assuming you are using a database to store session data), permitting much more data to be saved. (Me: I don’t save session data into database, so this doesn’t sound like a big change to me)
• Added the ability to store libraries in subdirectories within either the main “libraries” or the local application “libraries” folder[...] (Me: Finally. It has always pissed me up for not being able to organize my libraries)
• Added the ability to assign library objects to your own variable names when you use $this->load->library() [...] (Me: Yes, I’ve been wondering why this was not available in previous versions, when it DID with controllers and models)
• Added controller class/method info to Profiler class and support for multiple database connections.
• Improved the “auto typography” feature and moved it out of the helper into its own Typography Class. (Me: I didn’t pay notice to this feature. Looks like a VERY useful class now. Must make use of it)
• Improved performance and accuracy of xss_clean(), including reduction of false positives on image/file tests
• [...]
• Added support for mb_strlen in the Form Validation class so that multi-byte languages will calculate string lengths properly. (Me: So it didn’t make use of mb_strlen() in the past? OMG!)

With many other new features and bug fixes, this is definitely worth an upgrade. Way to go, CodeIgniter!

Update: Sorry, forgot this. You can download the latest version here.