It most likely would prevent you from playing anything HDCP. HDCP is illegal (?) to reverse engineer, and there are special versions of HDCP2 specifically for HDMI. You need a license and a verified device for HDCP.

That might not matter much for an ordinary PC, but this Steam Machine will be competing for the living room with the PS5 and Xbox which have Netflix, Disney, HBO, etc; Not sure if things like Spotify are HDCP-protected.

It will be interesting to see how Valve works out the kinks for that. Honestly in general it'll be interesting, because putting those things on Steam Store basically turns Steam Store into a general software store instead of a game store. And the only cross-platform store at that.

With iOS and Android being broken open, you could have games be completely cross-licensed. I'd say other software too, but sadly with everything going the subscription model, you usually already have cross-licensing, in the form of an account.

Part of what you're paying for is the right to use the trademarked tern HDMI, just like how the USB Consortium charges you stupid money to use the USB logo.

The suit over usage of "HDMI" in a reverse engineered version would wind up arguing whether or not HDMI is a genericised term and the HDMI Forum would lose their trademark. They will throw every cent they have into preventing such a decision and it'll get ugly

Yes, that might work. Strictly, HDMI is a registered trademark that might have strings but you could always say something like EIA/CEA-861... compatible instead

It's called nominative use, and describing a thing as "HDMI compatible" is permitted.

One doesn't get to use the logo or even the typeface, but that's not a dealbreaker at all for the purposes being discussed here. Words themselves are OK (and initialisms, such as "HDMI," are just a subset of words like nouns and verbs are).

The wiki has some background: https://en.wikipedia.org/wiki/Nominative_use