@ankurk The issue right now is not “if” it is possible to write a backend in PHP, but more a matter of what you can handle in your timeframe. For PHP right now there are MANY frameworks that allow you to build a REST API. Many of the more modern frameworks have REST functionality pre-baked like (Some WAY easier than others):
- Symfony 2 REST APIs with Symfony2: The Right Way | William Durand
- Laravel Laravel 4: A Start at a RESTful API (Updated)
- Zend Framework 2 Getting Started with REST and Zend Framework 2
- Code Igniter 2 Working with RESTful Services in CodeIgniter
There are plenty of others as well (there are more PHP frameworks I know of than I can name stars in the sky). That being said if you are going to take the time to learn REST, Ember, and a PHP backend I would stay clear of Code Igniter myself (I won’t derail this thread with my rantings), any of these others should be able to work for an Ember application.
If you are willing to reach out a bit, the Node framework @tarasm mentioned looks pretty easy, also you will find a lot of support from the Ember community for Rails (Rails) as well as Django (Python). Neither of these frameworks are particularly hard to learn either.
Keep in mind if you intend to use Ember Data you will need to have a fairly intimate understanding of the way IT uses REST. This is most likely NOT the way your framework will implement REST out of the box. Or else you will be in for a world of hurt trying to debug not only your Ember app but also your REST server as well. As such, you may want to avoid Ember Data right now (at least till it hits 1.0)
Your REST backend could be written in anything (I’ve personally seen Java, Ruby, Python) that can implement a REST strategy.
Best of luck, I hope this wall of text is not too long.
PS for full disclosure: the articles I linked are not vetted by me, I just found them on a quick google search. The only REST implementation I have done in PHP was in Symfony2, and I found it a bit lacking using the FOSRestBundle.