Note that this project is completely experimental. There is actually no need to publish issue, the whole project is under heavy construction.
First, you have to install Electron. You can do it globally using npm install -g electron-prebuilt.
Then use bower install to install several components.
You will need to build the sigma package. Go to bower_components/sigma/ and run grunt build.
Actually, this viewer uses the fresh new WebSocket pipe form GraphStream. You can get it and run the demo inside src-test/.
Once the server is running, you can run the viewer using electron main.js inside this directory.