When I started the Audio library, a nice GUI (like Puredata or Max/MSP) seemed an impossibly distant dream. Then, in this forum thread, I learned of the open source Node-RED project.
Over the last few days I've been coming up to speed on modern Javascript tools like jQuery and D3, to hack Node-RED into a GUI front-end. Much work still needs to be done before this is usable, but I'm pretty excited about the possibilities!
Update: a live demo page is now available. :)