DHN is the Digital Humanitarian Network of which HEF Help Earth Foundation is a member.
"The purpose of the Digital Humanitarian Network (DHNetwork) is to leverage digital networks in support of 21st century humanitarian response. More specifically, the aim of this network-of-networks is to form a consortium of Volunteer & Technical Communities (V&TCs) and to provide an interface between formal, professional humanitarian organizations and informal yet skilled-and-agile volunteer & technical networks."
List of member organizations http://digitalhumanitarians.com/partners
Please follow them on Twitter https://twitter.com/Digihums and fellow partners of DHN