The Adobe Integrated Runtime and Adobe Flash Player use AMF to communicate between an application and a remote server. AMF encodes remote procedure calls (RPC) into a compact binary representation that can be transferred over HTTP/HTTPS or the RTMP/RTMPS protocol. Objects and data values are serialized into this binary format, which increases performance, allowing applications to load data up to 10 times faster than with text-based formats such as XML or SOAP.
AMF3, the default serialization for ActionScript 3.0, provides various advantages over AMF0, which is used for ActionScript 1.0 and 2.0. AMF3 sends data over the network more efficiently than AMF0. AMF3 supports sending int and uint objects as integers and supports data types that are available only in ActionScript 3.0, such as ByteArray, ArrayCollection, ObjectProxy and IExternalizable.