Why bother with Varlink IPC, and why now?

The Varlink IPC has been around for a while, but recently we started using it heavily in systemd. In this talk I'd like to explain what Varlink IPC is, and why we are now adopting it so heavily. And I also want to explain why I think that Varlink is a good candidate as IPC of choice for any Linux software, both low-level and higher-level. We'll compare it with D-Bus in particular, and highlight where it shines (and where it doesn't shine so much).