Local Wireless Multiplayer is the latest huge feature to be added to the quite amazing Nintendo Switch emulator project yuzu.
For the official Switch hardware, this feature would allow two (or more) devices to connect up and play together. The way it works with yuzu is different to how it works on the Switch directly though, with it not being compatible with the Switch or other emulators. Sounds like a pretty extensive feature for yuzu too, with a whole virtual room system much like multiplayer lobbies you would find in various PC games. It also means you don't need a Nintendo account and it doesn't touch their servers.
With various public rooms available, and users who are fully Verified with yuzu directly will be able to host public rooms too. For people who don't want to do any verification, they will still be able to make rooms but they won't be listed publicly.
Sounds pretty great, giving you even more ways to play with others.
It's currently in their Early Access build until it's ready to be fully public.