Abstract: An aircraft interface apparatus for providing communication between an aircraft system and a device for use on an aircraft comprises a first communication means for providing communication with the aircraft system, and a second communication means for providing communication with the device, wherein the aircraft system uses a first data format and the device uses a second data format, and the apparatus further comprises: —an interface processing resource that is configured to receive data in a first format from the device and, in response, to output data in the second format to the aircraft system and/or to receive data in the second format from the device and, in response, to output data in the first format to the aircraft system.

Abstract: A content distribution system comprises a server, a plurality of clients and means for distributing a plurality of items of content to the plurality of clients, wherein each client is configured to transmit at least one message to the server representative of portions of the items of content that are present or not present at that client, and the distribution means is configured to determine from the messages portions of the items of content that are missing from at least one client, and to distribute the missing portions of content to the clients according to a multicast protocol.