After reading a few articles I felt like I finally figured out what Urbit was and wrote down my sense in a Tweet thread: https://twitter.com/ianbicking/status/1249862161758916609

In summary: Urbit is a functional/deterministic VM. That's mostly it. It runs a bytecode called Nock. The only language that really compiles to Nock is a weird language called Hoon. Because the VM is functional and deterministic, it is (in theory) also portable – you pick up the (ever-evolving) VM image and move it somewhere else, and it should act the same. Since the VM may move around there's also an identity/networking layer so you can talk to the VM wherever it is.

Right now Urbit is a program called u3 (runs on Linux or whatever) that runs Nock programs. OS 1 is such a program that does a couple things. It's unclear to me if they've really built an OS or just a library of routines that can be used to build a single multipurpose application.

The most direct article I found was "Review of Urbit": https://medium.com/@noahruderman/review-of-urbit-e7cc4c35f14...

Urbit's own "Common Objections to Urbit" was helpful, in a methinks-he-doth-protest-too-much sort of way: https://urbit.org/blog/common-objections-to-urbit/

And that article pointed me to "Houyhnhnms vs Martians" which was helpful though also as weird as Urbit: http://ngnghm.github.io/blog/2016/06/11/chapter-10-houyhnhnm...

While some people say Urbit is feudalistic, I tend to agree more with those that call it simply obscurantist. More occult than fascist.

That "Review of Urbit" is the best post I've read on it, thanks for sharing.

people here are describing Urbit like they're discussing the meaning of the monolith in 2001, or the true meaning of Christmas. I like your take because you're describing what the code is, rather than the objectives or use-cases. it feels like TempleOS to me because (to me) the code is the point. it's an exercise towards creating a specific architecture as an end.

Nobody really "gets" Urbit - you're just supposed to nod amicably whenever someone brings it up.

In all seriousness, it's nice to see that the Urbit peoplo are actually making substantial progress on... whatever it is they're doing. I love huge, totally outlandish projects like this.

I believe it's an attempt at a truly distributed OS, but it is buried in about 10 miles of unnecessary obfuscation and wordplay. Apparently now it is a Slack-clone as well.

It's a:

hierarchical

p2p network

of virtual machines

running an unusual, but lisp-like, OS

where the OS state is a pure function of a stream of input events

That wasn't too hard, was it? ;)

It seems similar to Tim Berners-Lee Solid. I guess the idea is to have a sort of pod of local data and a peer to peer system that enables people to connect those pods and build services on top of it.

That's about what I got from reading through the webpage.

I'm no expert, this stuff is definitely over my head, but here's my attempt to understand it: Let say you want a computer in the cloud. Today you probably do that by paying someone like Linode for something like a VPS. But under that model, Linode still has a ton of control over your computer in the cloud. With Urbit, it's distributed, so you aren't renting access to your cloud computer from some entity that has more control over it than you do.

Urbit isn't that distributed since your planet is running on one VPS.

(As an aside, the whole "$PROVIDER is going to hack into my VM" thing is pretty overblown. The cloud has existed for over 10 years and the worst that happens is the provider deletes all your data and you restore from backup onto a different provider. You do have a backup that isn't on the same provider, right?)

Walmart demands or strongly encourages that their suppliers not run on AWS, and Amazon is being investigated for spying on FBA data to enrich their own business. Other AWS competitors like B&H don’t host there out of fear of data safety and business continuity.

The worry is not that your provider will hack you, the worry is that your provider will silently steal your trade secrets.

Cryptographic keys that control identity and money are good distilled examples of this.

There's still no evidence that Amazon has ever done this. AFAIK potential customers are more concerned that AWS will use utilization metadata as a proxy for their customers' financials, like Facebook was using Onavo traffic data to decide which startups to buy and which to clone.

What VPS? Do you have to provide it yourself? Or is it assigned to you and managed by someone else? (I see a note in the article about "in the future, free hosting", but I'm not sure what that means.)

Yeah, you provide it yourself.

Cool thanks, in what sense is it distributed then?

Everybody having their own VPS is far more distributed than Facebook/Twitter/Slack but it's less distributed than some of the social blockchain systems. They have some good commentary on this point: https://urbit.org/blog/common-objections-to-urbit/#gov

Got it, so the social features are distributed (like Mastadon/Email are), but the OS install itself is not distributed?

Just read the source code /s (I still don't get it how they code in this mess)

This may be more to the point: https://urbit.org/understanding-urbit/urbit-os/

It's also just a programming language VM with focus on distributed apps and some opinions on network architecture.

That's the "what" it's just that the "how" (fucking hoon/nock) and "why" (moldbugs weird shit) is such a fucking rabbit hole that it obfuscates the very straight forward and uninteresting "what".