RAP includes a publisher API library, which is used
by feed handlers to format incoming market data, and send data
to subscribers by user datagram protocol (UDP) multicasting.
Developers can use
the publisher API to develop custom feed handlers.
Publishers accept incoming market data messages and send those
messages into RAP. RAP data stream (RDS) templates
describing the message formats are used by the publisher API to
format the messages into packets. The publisher API then sends the
packets across data streams to subscribers.