Business is a PHP library to help you to perform date and time calculations in a business context. With this library you can easily determine booking dates, the number of business days within a given period or the next opening date of your shop.
Create a simple table with sorting and paging using AngularJS to present data from a Symfony2 REST API powered by Hateoas.
Swap is an exchange rates library for PHP allowing to retrieve exchange rates for currency pairs. It supports multiple providers such as Google and Yahoo finance, the European Central Bank and more.
FOSRestBundle makes it easy to create standardized REST APIs but handling entities with camel case fields can lead to boilerplate code. Since version 1.4 there is a convenient way to handle these cases.
The Symfony2 Expression Language is a very great component allowing to create expressions that can be evaluated and compiled into plain PHP. One of the use cases I'm thinking about is a pricing engine that could be used in e-commerce softwares.