E.D. is not open source software. It is copyrighted by the authors.
The author granted each User of GitHub a nonexclusive, worldwide license to use, display, and perform the Content through the GitHub Service and to reproduce the Content solely on GitHub as permitted through GitHub's functionality (for example, through forking).
This project has been forked from etherdelta and intends to maintain the front end here on github. This fork is not "open source" by any definition of the OSI but is more based on the TOS of github that allow it. The plan is to document and explain the entire interface to the backend.
The author's of etherdelta has some strange misconceptions about the github license, so here are some pointers etherdelta#241 etherdelta#86 etherdelta#134 etherdelta#169 etherdelta#200 etherdelta#250