Net::Nmsg is a perl binding to libnmsg, the reference implementation of
the NMSG binary structured message interchange format. The NMSG
documentation describes the format as:

  The NMSG format is an efficient encoding of typed, structured data
  into payloads which are packed into containers which can be
  transmitted over the network or stored to disk. Each payload is
  associated with a specific message schema. Modules implementing a
  certain message schema along with functionality to convert between
  binary and presentation formats can be loaded at runtime by libnmsg.
  nmsgtool provides a command line interface to control the
  transmission, storage, creation, and conversion of NMSG payloads.

WWW: https://tools.netsa.cert.org/confluence/display/tt/Net-Nmsg