No guesswork needed.  The best stats we currently have indicates that PHP 4 is still 60% of all PHP websites.  Its been about a year since PHP 4 end of life was announced.  At the time it was 75% or so.  So approximately a 15% drop in a full year, after PHP 4 was announced end of life.

It just doesn’t make sense for us to exclude 60% of all potential CodeIgniter sites at this stage of the game.

CodeIgniter will not be dropping support for PHP 4 anytime soon

Let me lay it on the table here.  I like PHP 5.  I dislike PHP 4.  The other CI dev team universally share this opinion to varying degrees.  I am NOT making the argument that we should support PHP 4 on any type of philosophical or technical argument.  This is purely a numbers game.  If we could drop PHP 4 support tomorrow from a business perspective, we’d do it in a heartbeat.

On a technical level, this has been argued to the point where its gone from interesting, to funny, to boring, and now its back to funny again.  There is nothing in CI that prevents you from taking advantage of pure PHP 5 in your own apps (this is what I do in BambooInvoice).  CodeIgniter itself uses different “base” files for PHP 4 vs 5, and the end result is that in real, practical, functional terms, there is little to be gained from recoding CI in pure PHP 5, particularly in light of the market numbers.

In the article I link to above though, I write this, and I will conclude here as well.

So what are our plans for PHP 4 support?  We make software for the real world.  I assure you that when PHP 4 becomes as irrelevant as PHP 3, that we’ll drop support for PHP 4.

Derek, that was the most complete, concise and convincing answer I have seen yet.  Thank you very much.

I didn’t realize that CI includes separate code for PHP4 and PHP5.  That’s a very good idea.

That’s awesome, thank you for the update, and a wise decision I must say. Even though from a technical point of view I am a tiny bit disappointed, as are some other CI developers I assume (I bet you are too, Derek), it is logical that you guys have chosen to follow this path, seeing as how it’s important for your business. Business comes first and that goes without a doubt.

Will there be any significant changes to CI’s core / architecture / structure when v2 is to be released, or will things mostly remain in the same fashion, except with a few minor additions and closer integration with EE? Or is this perhaps hard to say at the current stage of development? I’ve read about integration of Jquery into the framework and that’s wonderful, are you guys also planning on adding ‘authentic’ ORM, and maybe things like, a user management module? Just brainstorming here you guys. Maybe you’re not thinking about this stuff just yet and just want to get EE2 up and running. Whatever the case may be, I’m very excited about the great work which I know you guys will put in, looking forward to it!

Firstly, let me say: I have no advance knowledge of EE2 - I know just as much as you guys.
Edit: This post got really long, skip to the bottom for the “bottom line” text.

In the beginning Rick created the Expression and the Engine.

Now ExpressionEngine was powerful and brought new ideas to the CMS field, and people were using ExpressionEngine as a framework creating amazing web applications centered around content.

And Rick said, “Let there be CodeIgniter,” and there was CodeIgniter. Rick saw that the CodeIgniter was good, and he separated the CMS from the framework. Rick called the CMS “ExpressionEngine,” and the framework “CodeIgniter.”

But, really - pMachine was EllisLab’s first product, blogging software. In 2004, EllisLab’s replaced pMachine with an amazing CMS called ExpressionEngine that had much cleaner code, was modularly designed, and a bucket full of features. Since it’s release, EE has been known for stretching the boundaries of what can be developed with a CMS. Really, it’s not your Mullenweg’s Wordpress - I’d be willing to say 70% of my client’s websites could have been developed in EE and it would have saved them about $600 each time.

So, Rick and team see that people are taking EE and essentially using it as a framework and making some pretty cool stuff with it. So, Rick’s like, “Yo dudes - let’s clean up the core of EE. The meat and potatoes that really makes it work. And release that bad boy for free.” And everyone else was like, “OMG - yes!”

So, CodeIgniter was released and as we all know, it’s the best thing to grace our careers. Now, ExpressionEngine and CodeIgniter have been following these two separate tracks since day 1. The tracks are parallel to one another - but still, separate tracks. If EE gets some crazy-insane new method that sticks cooks up Mozzarella sticks for you, use CodeIgniters are going to have to wait a little bit before we see it. The dev team has done an excellent job of sharing with the CI community but it’s a bit of manual labor on their part and let’s be honest, CI isn’t paying any bills.

So, earlier this year (or probably last) Rick was like, “Yo dudes - that framework we pulled out of EE… let’s build the next version of EE on top of it.” And everyone was like, “OMG - yes!”

So, now, we get a full-stack content management system that is pwntastic built on top of our pretty little framework here. When EE needs a new class that could benefit the rest of the world, or when a security issue gets patched - all of this is going into the CI core. Guess how easy that is to get into the SVN and the next release… seamless! Rather than having two separate products, on two separate tracks, we now have those two products on the same track.

Bottom Line: ExpressionEngine, the lifeblood of EllisLab’s, will directly rely upon the innovation and hard-word the CodeIgniter community puts in every single day. Our community, and for us freelancers - potential client-base, has grown significantly with this announcement.

As the amazing people here spot bugs, send in bug reports, ask the easy question (and answer the tough question) of “why?” we will see CodeIgniter greatly improve. Personally, I think the tempo of changes (if you’re an SVN person) and new releases will speed up considerably.

CI isn’t paying any bills

@Michael,

CI is a huge drawcard bringing developers to Ellislab products and services, ExpressionEngine benefits simply by being related and vice-versa.

CodeIgniter sticks out because it is a well documented and discussed framework among the few out there, whereas ExpressionEngine simply gets buried in CMS search results.

Don’t tell anyone CI doesn’t pay bills, even if indirectly.

PS. It’s certainly helping to pay my bills.

Don’t tell anyone CI doesn’t pay bills, even if indirectly.

Completely agreed wired, I should have stated it better: CI doesn’t directly pay EllisLab’s bills, although it does an amazing job getting ExpressionEngine and EngineHosting in front of people.

It’s certainly helping to pay my bills.

Ditto. :D