It is distributed. The website should have a copy at /ipfs/QmRaS4AZriMzw9nekub7hojTnvQYsVTDqkYG7BggQsexNt (check TXT record). You just need to access it over the right protocol.

But I thought ipfs-js would make it run today within the browser...?

To use js-ipfs, you still need to host the script somewhere. Doesn't help when the whole host doesn't respond.

Right, ok, but then ipfs.io is already using ipfs-js itself? Because some time ago I checked and the reference impl was python, and the ipfs-js port was not complete yet.

(IPFS dev here)

js-ipfs, the Javascript implementation of IPFS, has made a lot of progress in the past 6 months. It's still early but totally usable.

We've been working on go-ipfs and js-ipfs interop so that browser nodes can talk to "native" nodes. It's not fully ready yet but soon. This will open a lot of doors for a more advanced network and applications using IPFS.

See https://github.com/ipfs/js-ipfs.

As for your question re. ipfs.io using js-ipfs, the answers is no, it doesn't use js-ipfs implementation yet.

Is there a working ipfs demo page anywhere? I've had a look around and can't find one (the closest appears to be Orbit, but the ipfs-js version is down).

I'm particularly interested in using ipfs pubsub capabilities. It looks like an interesting way of allowing multiple users of a web app to talk to each other without needing (much) server side support.

Unfortunately there's no proper demo page :/ We're working on improving the docs (we know this is big issues atm).

There's an old version (from June) of Orbit at http://orbit.libp2p.io which you can try. Much has happened since and we're working on bringing the js-ipfs version Orbit back to a working state.

Re.Pubsub, I'm personally also very excited about it! :) The specs and general info are located here https://github.com/libp2p/pubsub. go-ipfs merged pubsub into master some time ago with this commit https://github.com/ipfs/go-ipfs/commit/e1c40dfa347e38bdc9812... and we're working to get it into js-ipfs here https://github.com/ipfs/js-ipfs/issues/530.

Can I just take a moment to talk about how happy I am that the IPFS team is actually taking protocol documentation seriously, allowing for multiple implementations and the ability to understand how the protocol works?

IPFS and Matrix seem to be the only teams doing this: Dat and SSB have vague protocol documentation at best, only documenting bits of the protocol at all.