I got this from the EDDN thread. Its possible I missed one. If you want to develop a tool which is using EDDN data the below should get your started. Note: There are more tools out there using EDDN then code snippets listed below.
Note: There are authors in the thread who said they would be willing to help commanders with code and/or examples on request. So if the below doesn't cover what you need please post a request for it in the EDDN thread. You probably will be surprised....
Tool: (intelligent) EDDN subscriber in python.
Author: kfsone
Annoucement: here.
Tool: EDDN subscriber/listener written in C# (.Net)
Author: maxh2003
Announcement: here
Tool: EDDN subscriber/listener written Python (version 2.x or 3.x is unknown).
Author: K Kinnison
Announcement: here
Tool: (minimal) Node.js listener for EDDN
Author: Andargor aka little red devil...
Announcement: here