Black screen with AMD graphics card

Since upgrading to Debian unstable I can't boot my system. It would show some text on a black background for a while and then the screen goes black. Ctrl+Alt+F5 doesn't work. https://ipfs.io/ipfs/QmRhCQNpCzSb2QAA5erUkFjXhVbuAS4czWfNxuf6iUMzRS

What is the mailing list software used by lists.debian.org?

I think it's not GNU Mailman. What is the software used for official Debian mailing lists? Is it free software?