It’s more likely than you think!
http://toadking.com/retroarch/index.html
Spent the last two days working on this, and got surprisingly far. Video seems to vary by browser (Firefox Nightly sits around 59 FPS while Chrome gets closer to my screen’s refresh rate of 59.98) and audio is not in for now, but this pull request in emscripten looks promising: https://github.com/kripken/emscripten/pull/1136
The real kicker will be how well it performs when I actually get something running on it.
Amazing
Ha! That’s awesome, man. Good shit 
Awesome, good job!!!
Updated the page, now it can play games!
Wow, impressive work Toad King
Where is your limit guys? 
Amazing
Updated with sound support (works best with vsync off)
Never expected it to get this far when I started. The rest of the issues are really just issues with video/audio sync which is kinda out of my hands with the browser.
Not working for me? Mozilla + disabled scriptblockers still nets me a black screen for Actraiser, SupermarioRPG, Rampart and The 7th Saga, the 4 I’ve tested.
Getting this error: WARNING: getProcAddress failed for glEGLImageTargetTexture2DOES
Wish I was a computer wizard, you Retroarch guys are amazing. Can’t wait to see this running at the local public libraries!
That warning is normal.
Check the javascript console in your browser, it might be hitting some other error that doesn’t get logged in the textarea.
Ran this on my chromebook arm [ running 31.0.1631.1 (Official Build 223276) dev ]. gambette and genesis plus gx (Sega Master System) were usable, but not always fullspeed.
Just a bump to notify people: Latest Firefox release has Web Audio support and should work well with the cores on my site. If you get audio crackles/gitches, try setting the rate control under audio settings to 0.0 and restarting Firefox Avoid loading up other tabs before the one with the emulator.
Added FinalBurn Alpha to the demo page.
NOTE: The FBA javascript file is huge (40MB+ uncompressed) so it will hang your browser for a bit while loading. Also, there might still be bugs with some games not working due to unaligned memory access issues not fixed. Please report any if you find them.
Oh man, just got done playing some third strike in mah browser. Bananas!
Good work, dude.
Hi, I did not find any documentation how to build retroarch with Emscripten, can somebody send me simple steps ?
I think it’s currently not building properly, but it should ideally be a matter of building a libretro core and then statically linking it to RetroArch with target=emscripten