About a month ago streaming responses (#2935) landed in master. My concern with the current implementation is that it has no transport abstraction. It will always assume a CGI-like environment where echo delivers to the client.

The most important feature of Symfony2 is the HTTP abstraction it provides. Ideally we would have streaming supported in this abstraction as well. This would allow using Symfony2 with other web servers, such as AiP or mongrel2.

I have started some work on this in my output-stream branch. @fabpot if you like this approach it would be great if you could complete it, as I really don't have the time right now.