I also got some code-share and collaboration features working, but got a bit stuck on fonts. But I can appreciate your feeling of 'how cool this is'
I ground to a halt once I realised I had no barrier to entry, ie it could be cloned very easily. Always an issue with Web Development I guess. Plus I hate what modern browsers have become in recent years and not sure I want to target such a fast moving platform. I got burned once already with WebStart 'warning this app might do something scary' and certificate fiasco.
I thought about some native binaries, but I know I am kidding myself. I had an ios app that was pixel cloned within 6 months. But somehow a web app feels like publishing straight into public domain.
For fonts, I just went with a simple raster bitmap font and pixel grid storage format. Creating these limitations makes it easier for me and for developers and artists. I choose 320x180 because it fits the 16:9 perfectly, which would make full screen ideal on most monitors.