We are aware of kbfs, ipfs, and several other systems. There are many trade-offs one can make in this space, and I think Upspin's set of tradeoffs is somewhat unique.
One reason we started this project instead of contributing to others is that it's not clear that the trade-offs made by extant systems are really working for users, at a fundamental level. Maybe Upspin's will, maybe they won't. We'll see.
We wrote a bit about this in https://upspin.io/doc/overview.md but there is still more to say. I filed an issue a while back to write a substantial document that compares Upspin to other systems. Hopefully the community can help us flesh it out in time: https://github.com/upspin/upspin/issues/177
Seems to be very much in the space of kbfs and IPFS.
For the folks who are building this: can you compare and contrast this to both kbfs and IPFS? Why have you chosen to start another project in an already crowded space instead of contributing to either of those projects? They are both open source and much further along in development . . .