Works as intended. I can now contain spying websites on their own sandbox and use M365 on multiple accounts simultaneously.

Simply awesome

Can someone explain to me what's the difference of Multi-Account Containers with the new site isolation feature in Firefox? Is it still useful to have the multi-account containers?

Such a useful extension. I'm a freelancer who works part time for four different companies, all of which have onedrive and sharepoint sites plus other systems. Being able to simply open onedrive/sharepoint etc in the 'company 1' tab then the 'company 2' tab and have it log me in to the right place automatically without hassle is a massive time saver and so useful. Love this extension.

Awesome to separate your buying from banking etc.

Very close to perfect! A lot of great features! Excellent for both security and privacy. Just a couple of points keeping it from 5 stars:

1st: We need an option so that all tabs set to open in a container by default won't prompt the user to ask if they want to open a link in its assigned container. It should just do it.

2nd: "The Manage Site List..." menu needs an option to manually enter a web address. Currently the only option is to use the address bar button while navigating, but this can break some re-direct heavy sites. Slack logins, for instance, may go through several different corporate domains in an instant and will break in horribly painful ways if one of those URLs isn't allowed to open in the container holding the login cookie.

3rd: Mozilla VPN is a good idea, but its implementation would be less vulnerable to traffic profiling attacks if it were on by default on all containers and each individual container had a separate opt-out option instead of the current enable option. I'd also like if the service weren't tied to specific Firefox accounts, or had a multi-account payment plan, so that I could use it on my work and home accounts at the same time.

4th: This is just a wish-list thing, but I'd absolutely adore it if you allowed us to use third party VPN logins instead of Mozilla VPN. This would be really great for tunneling into VPNs tied to router networks in the home or at work as if the user were physically on location. A lot of companies do this for security and including this could really help adoption.

Address at least the first three of these and you'll get five stars!

The doc on GitHub says it works on FF 57+ but it actually it refuses to install on ESR that is v. 78 asking to upgrade the browser. Wrong documentation or what? It works on Dev edition (same Debian Buster computer).

Le falta muchísimo desarrollo a esta extensión. Es muy incómoda de usar. Tendría que ser algo más sencillo, más parecido a los perfiles de Chrome. Podrían convivir en una sola ventana, pero por ejemplo, si tengo una pestaña "personal" y yo quiero abrir youtube.com, me pregunta si lo quiero abrir ahi o en otra pestaña... y si lo estoy abriendo en la pestaña de personal, abrilo ahi... y no en laboral. No me preguntes siempre.

My checking account is in a banking container and opens fine. The credit reporting service they use would not open in the same container. The link would open in a new tab. Couldn't find another way to give this feedback.

When using youtube I need to restart the browser frequently because I get false "offline errors":

Connect to the internet
You're offline. Check your connection.

Deactivating the plugin after getting the error doesn't help. You need to restart firefox. Really annoying!!!