Cascading namespaces allows you to easily override Proem classes with your own implementations that will then be used throughout the framework.
A simple dependency injection implementation allows easy decoupling and configuration of individual components via DI containers (services) and assets.
The entire bootstrap process is event driven in Proem. This allows you to register a listener for events and easily inject your own code into the process.
Proem was developed from the beginning to be a PHP5.4 framework and takes advantage of a lot of the newer functionality provided by this modern version.
A permissive free software licence with minimal requirements about how the software can be redistributed.
Proem is open source. Everyone is free to contribute and help out as well as enjoy the benifits of others work.