TOP PHP frameworks in terms of number of books published on a given framework

To begin with, I would like to say that I'm not new to PHP 4 and 5, but I would not call myself an expert. The reason is that for a few years now, PHP and web applications are things that I do only in my spare time. I also haven't used all the PHP frameworks, nor I'm the expert in any of them. I'm basically looking for a framework that is worth looking into and which would save me a time, as I don't want to spend much time on weekends coding e.g. only user authorization or registration form validation. So far, I did some small jobs using Prado, CakePHP and now I'm starting to learn Zend Framework. I also heard lots of good about CodeIgniter and Symfony. Since, I couldn't learn all of them, I just wanted to find some way of determining which of them seems to be the most popular. I decided to check how many books on a given framework are available in amazon.com?

I chose this criterion because for a person that wants to learn a framework, examples along with explanation can be valuable. Apart from official tutorials, quick start guides and reference manuals, that are available on the websites of the frameworks, books can provide good introduction along with example applications. Additionally, a number of books, also shows to some extend, how popular a given framework is. I would imaging that not many authors would write books about unpopular frameworks. Off course, there are many other possible criteria that can be used to rank or compare PHP frameworks, such as documentation, community support, performance, fast availability of updates etc., but I think that the number of books somehow translates to the the popularity of a framework.

Method of comparison

I went to amazon.com and I performed advanced searches for books on a given framework written in English and published after 2007. A year 2007 was chosen because books older than two years may contain highly outdated information. A framework name was a keyword. Than, the number of books found was counted.

En example of a search criteria used is given below:

Results

The results are as follows:

	Zend Framework - 10 books (see the books)
	Symfony - 9 books (see the books)
	CakePHP - 3 books (see the books)
	CodeIgniter - 2 book (see the books)
	Prado - 0 books (see the books)