Matthias Noback has posted about some of his experimentation with Broadway, a framework of testing helpers and structure to create CQRS/event sourced applications. CQRS is a design pattern (Command Query Responsibility Segregation) that essentially defines the use of a different method for reading data than for working with it (ex: updates or creates).
At the Dutch PHP Conference I attended a workshop by Beau Simensen and Willem-Jan Zijderveld. They showed us some examples of how to work with Broadway, a framework for event sourcing, with full Symfony integration, created by the smart people at Qandidate.
During my two weeks of funemployment, before starting my new job at Ibuildings, I decided to recreate one of my previous projects using Broadway. As it turns out, it's a great framework that's quite easy to use and is very powerful at the same time. Even though it's not a stable package (as in, it's still in the 0.x version range), I think it's safe to depend on it.
Matthias found that one of the main features of the models in Broadway is the serialization of them for storage, but wanted to reduce the amount of time to handle that...so he created this library. He also talks about something that several have pointed out as missing in the Broadway structure: how to use "sagas". He ends the post with an update on his own tool, SimpleBus, that handles eventing and via message busses, noting that it's not going anywhere but if you use Broadway, there's no reason to use SimpleBus too.