[mootothemax]

Did you click the link? This is an example of a truly open solution, and it involves hardware.

And it wouldn't lead to me replacing my DLNA-based setup, hence my question.

I also question your description of "truly open," although that's me being a bit Stallman, granted.

[barista]

Isn't Miracast the open solution that is open and supported by many?

[0xndc]

Miracast isn't "open" - devices require certification, and the Miracast and Wi-Fi Direct specifications cost $200 each. It's also supported by relatively few devices right now (since, you know, certification), and I seem to recall there are some compatibility issues between manufacturer implementations.