If you use WordPress, you may be surprised to see that WordPress still supports PHP 5.2
PHP 5.2 was released in 2006, which is nearly a decade ago, and in the way that the internet ages, an impressively long time. In 2010, only five years ago, the last version of PHP 5.2 was released: 5.2.16. At that point, PHP no longer supported 5.2, but did apply security patches. True end of life hit in January 2011.
But back in 2006, when WordPress was getting off the ground, a lot of people were still using PHP 4. Not 5, 4. It wasn’t until mid 2010 that WordPress itself dropped support for PHP 4 (and MySQL 4). At that point in time, roughly 11% of WordPress installs used anything lower than 5.2 and this made it a pretty safe bet.
So why does WordPress still support PHP 5.2? Today if you look at the (not very accurate) WordPress stats, you can see that over 30% of people still use PHP 5.2
Back in 2010, WordPress was about 10% of the entire web. It’s double that today, so 33% of people on 5.2 is significantly larger than 11% back on pre 5.2, and with those numbers, it’s easy to see why it has to keep supporting PHP 5.2 … for now.
But the next obvious question becomes why is PHP 5.2 out there? And the answer is that WordPress is only 22% of the internet. Flip that around and remember that 78% of the internet is not WordPress. WordPress is not everything, nor should it be, so the webhosts of the world do have to consider than when they begin to upgrade.
Most major webhosts are in some state of killing PHP 5.2 with fire (seriously I am very excited for when it’s finally gone from DreamHost). When we upgraded people to 5.4, we found a lot of people who had very odd code out there that just didn’t work on 5.3 or 5.4, and upgrades broke them. We also found a number of people using WordPress who broke, mostly because they’d customized PHP 5.2 and forgotten, but also some who were on things like WP 2.x and were shocked, just shocked, it needed to be upgraded.
As developers, we want to be able to force everyone into a place where we can upgrade PHP (and WordPress) and have no compatibility fears. We want to use the new features of PHP to allow us to craft better, faster, more efficient code. We want to give users the features they ask for. But we can’t until everyone upgrades. And thus the vicious circle begins.
Would WordPress dropping support for PHP 5.2 speed up it’s demise? No. Not at all. Because WordPress is a drop in the ocean of the hassle that is upgrades. Do I think WordPress should drop support for PHP 5.2? Yes, but not the way you’re thinking. I would love to see WordPress stop supporting 5.2 in the sense that it should stop testing against it and worrying about backwards compatibility with PHP 5.2. It should check, on upgrade and install, that PHP 5.3+ is used and go from there. Heck, if it had a big alert “Hi, you’re on PHP 5.2, please upgrade!” on the admin page, that would be awesome.
But I don’t know that there are any PHP 5.3 (or 5.4 … or 5.5 or 5.6) specific features that absolutely require WordPress to be on 5.4 at this time. Frankly, that doesn’t matter at all because the issues with upgrading are far less related to where WordPress is going and more directly the cause of where servers have been. Most hosts grow organically, servers being built following a process and then (eventually) via an automated tool. But because of that, a lot of old servers and operating systems don’t lend themselves well to upgrades because they’ve been built rather … higgeldy-piggeldy one might say.
It’s that history, the drama of people not seeing the future 10 years ago, that puts many hosts in a position where upgrade is actually going to mean moving users to a new server with new features. And that is not something to be done lightly. We can’t just pick people up when we want and move them. There will be downtime, there will be outages, there will be delays. And because of all that, these moves take longer than you want.
This is not to say the hosts aren’t doing the right things, just that they take longer than anyone (especially the host) would like. And believe me. No one wants PHP 5.2 gone more than a web host.
