Interview with Andreas Kling about this (scroll down for english transcript): https://www.heise.de/news/Ladybird-Entwickler-im-Interview-W...

Ooh, ooh.

I'm on Ubuntu, and it looks like I need to upgrade to 22.04 before I can experience the build process for myself.

https://packages.ubuntu.com/search?suite=all&arch=any&search...

The repo itself is shockingly tiny: https://github.com/awesomekling/ladybird. Looks like it needs https://github.com/SerenityOS/serenity as well. https://github.com/SerenityOS/serenity/tree/master/Userland/... is 100kLoC which is also surprisingly small.

Acid3 tests for a few things that have been dropped from the standard, so if a new browser passes it 100%, I'm suspicious.

The browser has been under development for a while now. It's the built in browser for SerenityOS: https://serenityos.org/

There are 2 screenshots : one with a menu and one without . Which one is real ?

The one with a menu is the SerenityOS browser, not Ladybird browser. It is not supported on Linux. Ladybird is a demo of the browser engine used in that other browser ported to Linux, so it's very bare-bones and only has a URL bar.

does it have tabs because all i need is tabs

The SerenityOS browser has tabs (they're hidden when only one tab is open). Ladybird doesn't seem to have them yet (considering it also doesn't have all the other buttons), but I should imagine it's something that would be added.