Action Message Format (AMF) is a compact binary format that is used to serialize ActionScript object graphs. Once serialized an AMF encoded object graph may be used to persist and retrieve application state across sessions or allow two endpoints to communicate through the exchange of strongly typed data. The first version of AMF, referred to as AMF 0, serializes ActionScript objects and retains strong type information, capturing the public state of application data. AMF 0 also supports sending complex objects by reference which helps avoid sending redundant instances in an object graph as well as allowing endpoints to restore relationships and avoid circular references.
      An AMF Message contains information about an individual transaction that is to be performed. It specifies the remote operation, a local client operation to be invoked upon success or failure and data to be used in the operation. The structure of a response message is the same as a request message.
      The first field of an AMF message is the target URI which describes which operation, function, or method is to be remotely invoked. The exact format of the target URI is not defined by this specification. The client must use the naming convention established by a particular server implementation. An example of a convention might be to specify a fully qualified service name (such as a class name) using forward slashes to separate service hierarchy (such as class packages) and a dot to separate the operation (such as a public class method) from the service name.
      The second field of an AMF message is the response URI which specifies a unique operation name that will be used to match the response to the client invocation. Since the remote endpoint will use this field in the event of an error, this field is required even if a successful request would not be expected to return a value to the client.
      The third field of an AMF message is the byte length of the message body. This may be useful when it is necessary to split up an AMF packet without first decoding each individual message. If the length cannot be reliably determined, a value of (U32)-1 can be specified.
      The fourth and final field is the message body. The body contains the actual data associated with the operation. If the message is a client request then the body contains the client's parameter data that is passed to the remote operation/method. A list of arguments should be represented with a Strict Array type. If the message is a remote endpoint response then the message body may contain a result.
      Additionally, if the remote endpoint detects an error with the incoming client data and/or the operation requested, the remote endpoint will provide error information in the response message body.
      Social application — an application running on the technology of flash. Every day, they are becoming more popular among the users of social networks. Thus, the application provides the users involved and is designed for the widest possible audience. As a result, a social application solves two problems: the producers of applications get access to new markets, and users get rid of boredom and have an incentive to visit their web pages. According to the study, social application sector in 2009 added about 50% in 2008.
      Headers provide context for the processing of the remainder of the AMF packet and all subsequent messages. Notable uses for this construct would be for encryption of the remaining packet and/or authentication of the user to the server (username/password). Multiple context headers may be included within a packet. A header's name typically identifies a remote operation or method to be invoked by this context header. If a method is specified, it should conform to URI formatting styles using a forward slash '/' to delimit object and/or directory paths. When the header is bound for the Flash Player, it should target a well known method name on the NetConnection instance's client.