Self-Hosting on Gamers Nexus | what computer is that?

Video from GamersNexus on the importance of self-hosting, with some nice references like Rustdesk, Tailscale and Cory Doctorow

But I didn't understand, when they were showcasing a rack computer starting at around 20:20, who Wendell (the guy with glasses) meant with they who made that computer. What platform is that, what's its name?