First up, I can only claim to be an expert in Symfony2. My knowledge of other PHP frameworks basically consists of actively following twitter for things related to PHP, reading planet-php.org and taking the time to read up on linked mailing list threads and IRC chat logs. I have not been that active on the conference scene in the past few years, but the ones where I did attend I also tried to take a peek at what others are doing. Also this post is kind of exploratory to see what other people think, hopefully without inviting a flame fest upon myself. So with this disclaimer out of the way, I think the big 3 frameworks for the next few years will be Lithium, Zend Framework 2 and Symfony2.

Drupal is big, no question. Over the last years Drupal has become one of, if not THE leading CMS. Now imho one of the reasons for its success is that it's a huge enabler for non programmers to get setup with a gigantic set of features. But here at Liip our bread and butter is highly customized applications or in other words if you can get your project done by installing a bunch of Drupal modules, then we are not the right shop to go to. We do however use Drupal when it's the best starting point for development like we did with Migipedia. However we have in many situations found that we could more efficiently implement custom logic outside of Drupal and then integrate it. Now since we have chosen Symfony2 for all future custom development, the fact that Drupal8 will use Symfony'2 HttpFoundation component is huge, because it will make integration a breeze.

Liip is currently working on a news site. As news is all about being up to date, but still managing to serve a large number of users with milli second response time, we obviously run into a bit of dilemma. We can use Varnish to cache the content, but then we will need to use a relatively short cache time out or we risk not getting updates to our users quickly enough. A better approach is to use invalidation, where we can then set a relatively long cache time, but ensure that still no stale content is served. At Liip we provide a considerable budget for innovation available to all employees, so I figured it would be cool to use this to create a solution to allow us to move to cache invalidation for this site.

When talking about why people work on open source its often said that developers are just scratching their own itch. I have also read the innovators dilemma (actually I was referencing it quite a bit in my thesis paper) so I am aware that often innovation occur when someone gives a new twist to seemingly "solved" problem areas. I also realize that solving the same problem with a different approach is an important component here.

At Liip "Symfony2" started in production a year earlier. Well I say "Symfony2" because it was just our internal framework OkAPI enhanced with the current crop of at the time PHP 5.2 Symfony components (actually we also included the symfony 1.x routing component). The results were so convincing that we decided to switch to Symfony2 entirely. The big feature back then and today is of course dependency injection (DI) and the dependency injection container (DIC). I remember many discussion with Jordi back then, where we went back and forth on if Controllers should be configured in the DIC or not. In the end we did go with making Controllers DIC services. The other alternative is of course to instead just inject the entire DIC and let the Controller pull whatever services it needs straight from the DIC.