If you use Dat through its command-line app, you get real-time updates to the files shared using it.
CRDTs naturally fit with P2P/decentralized topologies, and we've generalized them in https://github.com/amark/gun which is the most popular (8K+ stars) open source (MIT/Zlib/Apache2) realtime decentralized database.
It is running in production on P2P alternatives to Reddit and other apps, that have pushed over half a terabyte in a day.
Dat is realtime. You are notified about updates as soon as they are distributed. In Beaker, the files-archive API has a `watch()` method to do this. If you're accessing a dat files-archive, you're participating in the syncing swarm and so you'll receive those updates automatically.
You'll want to use a UDP socket if you're streaming a high volume of data with low latency requirements, for instance for a multiplayer FPS. But Dat has been used to stream live video, so it's probably real-time enough for most Web use-cases.
Small aside: Comparing Dat to CRDTs is apples to oranges. It's like comparing Javascript to B-Trees; they're not quite the same kind of technology. In fact, the new version of Dat uses CRDTs in order to allow multiple users to write to a files-archive.
Append only logs have overhead that would make it a poor choice for most realtime applications, like GPS tracking, yes FPS games, google Docs, website creators, and many more. Basically any use case where data mutates.
In 2010 I used and built all my own custom event source system, I was the hugest proponent of this / append only logs. It was so futuristic. But 4 years in I hit all sorts of scaling problems and had to redesign everything from scratch and that is when I found CRDTs. On all accounts they are superior, in a mathematical or logical manner, because they are a superset to DAGs, immutable/append only logs, and many other popular data structures. Not apples and oranges.
https://dat-tiddlywiki.glitch.me
The UX definitely needs some improvement, but it’s just a personal project so far.