The file "runtime" is a binary blob, where's the source code for that?
I think moving the source to a source repository would be great, for people to improve over AppImage and adapt it to their needs. I'm tempted to upload it to Github, but of course you're the creator, so it's up to you
Besides, have you shared the scripts you use to help you develop AppImage? I'm very interested in stuff like the one you use to test any AppImage on several cramfs chroots, it'd be something of huge value for anyone wanting to make portable packages.