x11proto-dmx-dev 1:2.3.1-2 (armhf binary) in ubuntu bionic

 This package provides development headers describing the wire protocol
 for the DMX extension, used to set up a distributed multi-head environment
 with a single server acting as a gateway to multiple X servers on multiple
 machines.
 .
 More information about X.Org can be found at:
 <URL:http://www.X.org>
 .
 This package is built from the X.org dmxproto proto module.