This is using my gameboy emulator, binjgb[0], on the website! (well one of my gameboy emulators, heh [1][2]) It's been used as the emulator for GB Studio for a little while now, but I don't know how often people embed it in their websites, so it's really cool to see.
[0] https://github.com/binji/binjgb [1] https://github.com/binji/pokegb [2] https://binji.github.io/raw-wasm/badgb/
If this is the same emulator ejected by GB Studio when it exports to web, that makes sense. All GB Studio projects on Itch.io likely use your emu too!
https://itch.io/games/made-with-gb-studio
725 listed so far (lots of asset packs and tech demos I'm sure, but still.)
heh, good point! Most of the older ones are using GameBoy-Online[0] instead, since that was the GB Studio default for a while. But I think everything since GBStudio 3 should be binjgb.