Question: Is there a DI framework comparable to Google Guice? And what does Google use?

Answer: 
There is a recent one that looks very interesting called [Hypodermic](https://github.com/ybainier/Hypodermic/wiki/Registering-concrete-types), i haven't tested it but it looks pretty active
I am currently authoring one called [sauce](https://github.com/phs/sauce), whose design (and name) is directly inspired by guice. I still consider it alpha, but you may find it useful.