Kojo: an educational language inspired by Logo and Processing

"A modern, powerful, programming language called Scala to work with. You begin with a very small and simple subset of Scala, and progress to the level of Scala proficiency that you care to reach."

so basically it's a Scala IDE for easy learning and authoring, tried it quickly and it looks nice, though the UI is pretty java-swing style.

Please retitle. Kojo: and educational IDE based on the Scala language inspired by Logo and Processing.

How good is this for kids learning programming (compared to Scratch and others)?

tl;dr: it's a Scala IDE.

With an interactive, graphics enabled REPL like the one of Dracket or Swift playground. Also a visual programming tool and a set of libraries (Turtle!) for easy displaying graphics and playing sounds.

Looks nice at the first glance. This may be the first IDE/env I'd consider using instead of my Emacs :)

Yes, absolutely! It looks like there are lots of nice features.

But it's not a new programming language, and shouldn't be advertised as such.

(In fact, I now notice that their website doesn't claim it is. Where did the HN post title come from? Because it's just wrong. I can't update my original post any more.)