The IP Flow Information Export protocol (IPFIX) is an IETF Proposed Standard for the export of information about network flows in IP networks. It is the logical successor to Cisco NetFlow version 9, upon which it is based. The key innovations of IPFIX are the flexible definition of a network flow and the runtime description of record formats through templates based on a well defined, extensible information model. These allow IPFIX to export flow information from present as well as future networks, and make it applicable to network management beyond the network and transport layers. In this article, we describe the protocol, from its motivation and history through its design and implementation, and explore its deployment within a network monitoring research project.