For those users, there is uBlock Origin. Actually, I think it's the recommended suggestion by their developer for all users, isn't uMatrix no longer supported with uBlock Origin including many of it's features?

I'm still using uMatrix. I don't really understand why uMatrix was abandoned, its UI is miles ahead what uBlock Origin offers.

I haven't used uMatrix in years, but isn't the UI in uBlock Origin > More similar, do you know what's missing?

https://github.com/gorhill/uBlock/wiki/Blocking-mode:-medium...

Everything is missing? That left panel as shown in the screenshot is display-only, you can't click on it to allow/disallow anything (also: it's below the rest of the interface in my version, not to the left, which requires a lot further mouse travel).

...oh, I see, I have to first go into the settings to declare myself an able-minded human. That's quite the UX failure, hiding functionality behind an unrelated toggle at an entirely different place.

Having finally found the correct mystical incantation, I can answer your question. At first glance, that UI is incredibly confusing. Why are there two two columns to the right of every domain? What's the difference between making the left column red and the right grey, versus making the right column red and the left grey? What is the significance of the +'s and -'s in the various cells? That help page doesn't explain any of it.

What's really missing: uMatrix lets me see how many resources of what type were loaded from what domain. That's very helpful when finding out what needs to be unblocked: if a site doesn't work, I progessively whitelist third-party resources until basic functionality is restored. I then remove everything from the writelist that's unused. It doesn't seem like that information is available.

Also: with UBO it doesn't seem possible to enable javascript for just one third-party host, or enable everything except javascript? If I whitelist a host in the UI, it automatically enables static resources (img, css), dynamic resources (js), cross-site data (xhr) and frames. I'm not going to write manual rules every time I want to allow everything except javascript.

This is just from a cursory examination, so maybe the functionality is there, it's just unfamiliarity with the new interface. But from what I'm seeing, neither the UI itself nor the help page make a compelling reason to make the switch.

To allow disallow, click the smaller rectangles to the left, on mouse over they are grey and red squares.

>uMatrix lets me see how many resources of what type were loaded from that domain.

uBlock Origin > Logger (its an icon)

> enable javascript for just one third-party host

Red button (with more enabled) disables a specific resource in a nested-list UI very similar to uMatrix AFAIR.

Yes, I phrased that one badly. I meant to ask: how do I enable just javascript for a host, rather than also enabling css/img/frames? But that's more of an academic question since if you trust a domain to run javascript, you'll surely also load css and img from that domain.

Red button (with more enabled) disables a specific resource

I don't see it. Red button disables a specific domain for as far as I can see. It doesn't disable just one type of resource from that domain.

in a nested-list UI very similar to uMatrix

It seems this is the problem: uMatrix is most emphatically not a nested-list UI: it is an authorization matrix UI. It seems that UBO does try to incorporate some of uMatrix' features back into it, but in the basis it's still a one-dimensional blocklist. That's just not good enough for how I browse the web in safety.

If the missing functionality is there, I can't find it either and no mention in the docs.

Replying to myself to further refine my issues:

Why are there two two columns to the right of every domain?

The left column is for global rules (independent of the currently-visited domain), the right column is for rules specific to the currently-loaded domain. This is strictly inferior to uMatrix, which allows me to set rules for every part of the dns name (e.g. I can easilty switch between settings rules for news.ycombinator.com, ycombinator.com and even for all .com sites). So what's missing: source domain control over the rule I'm currently setting.

What's more, in uMatrix I could set a hard block on a toplevel domain (say, google.com) and then add a whitelist for a subdomain (say, mail.google.com) which would override the higher-level block. Since UBO only uses block (red)/ignore (grey), this kind of setup is not possible. So what's missing: an explicit allow/ignore/block toggle like in uMatrix.

What is the significance of the +'s and -'s in the various cells?

These are blocked and allowed resources, so there's some level of feedback there. But it seems that CSS resources are not included in those statistics at all, and images do cause a + to be displayed in the domain-specific row but not in the generic "images" row whereas third-party javascript gets a + in the domain-specific row and in the generic "3rd-party scripts row". So what's missing: I want resource type indicators rather than generic "+"

I'll repeat what I wrote as a response to the sibling comment because it seems to be a fundamental UI problem: the UI of UBO still seems geared towards a one-dimensional blocklist and is missing all the controls for two-dimensional control of [domains]x[resource types]. And after years of safely browsing the modern web with uMatrix, I can't imagine going without that control.