Last Sunday I decided it was time to organize a little bit my bookshelf. And there it was, a book I’ve completely forgotten about (I can’t remember why I bought it!): PHP 6 – Fast and easy web development.
The book was published in January, 2008. More than six years later, the latest PHP version is still
5.5 5.6 (it was 5.5 at the moment of writing the post but PHP 5.6 has just been released, which, in fact, makes the situation even worse). Apart from the fact that, clearly, the book authors are marketing genius (many people, not familiar enough with the evolution of PHP, would still buy the book today believing it had just been written), this also says something about the evolution of PHP.
According to Wikipedia, PHP 5.0 was released in 2005. PHP 6 was supposed to add quite a few nice features to PHP 5, specially the integration of Unicode support but this later part failed and it was decided to port back some of the other “PHP 6″ features to PHP 5. And 9 years later we’re still there (I mean, with PHP 5). Yes, things seem to have speeded up as of the late with the PHPNG (PHP Next Generation) performance improvements supposed to become the foundation (together with other syntax improvements) of PHP 7 (they are skipping PHP 6 to avoid confusion with, for instance, my book) and other initiatives like HHVM (just in time compilation for PHP).
Still, given the huge importance of PHP (remember that WordPress, which itself powers 23% of all Internet sites, is mostly written in PHP), I think we should have seen a much more continuous progress of the language. I’m not knowledgeable enough about the PHP community to explain why is that but my feeling does not seem to be shared by most hosting companies that, to avoid compatiblity problems, prefer to stick to old versions of PHP (including versions which are, or going to be soon, not supported anymore).
This, in turn, forces software like WordPress to not update their minimum requirements (currently PHP 5.2.4) in a kind of chicken and egg problem. The result, more than 20M of people (only counting WordPress users) running their sites on outdated, and potentially insecure PHP versions. If you have some time, take a look at the two discussions around these tweets (note the date difference between the two), helps to get more context on the complexity of the situation.
And, in the meantime, anyone interested in buying my PHP 6 book? It’s in pristine condition!
UPDATE: You may want to take a look as well to the reddit discussion on this post (>650 comments)