[edan]

We use both thrift and protobuf, and my experience with both has been very positive. I feel that protobuf is more mature and has better performance for the most part, but thrift does provide built in RPC support, which protobuf doesn't.

I think if I wanted to implement RPC I'd use thrift again in a second, and if I was sure I wanted only message passing/serialization, I'd go with protobuf again.

The other main factor is language support - while they are both very good at this, they have slightly different support, and if native PHP support is important to you, Thrift is a better choice, as well as for a few other languages as well.