Dang, that reminds me of some OS I saw back in the 90s, wasn't Windows or Mac, tho.
It's right there on the top of my brain...
5ish minutes of searching later...
OS/2. That's what it was. That's what BeOS reminds me of after seeing like 4 screenshots and no other context.
I have no idea what this Dano leak is, or what the context even is. Was some kind of software called "Dano" leaked, or is it the leaker's handle, or what?