Rendering web pages progressively

I am delivering my php scripts from a new Apache server on CentOS delivering them only at the end of the loading. What is a pain, especially for pages being used by iOS apps just needing the xml section even if the script goes further, or when presenting information while they are generated.
How do I change this behavior?
Thanks,
Fabrizio Bartolomucci

See original post by Fabrizio Bartolomucci