RDS offers a Berkeley socket API which allows messages to be sent to multiple destinations from a single socket.

RDS is now included in the Linux kernel, and also available for older kernel versions via the The OpenFabrics Alliance's OFED distribution.

Development git trees may be found here.

RDS 3.1 Wire Specification is here.

rds-tools git repo is here. Tarballs of rds-tools releases also available in the download section.