Reader Luke Teaford let us know about TANGUY – a browser-based synthesizer.
You play it with the QWERTY keyboard. – and + shift octaves up and down. OSC 2’s FM comes from the sine wave of OSC 1 (so it has to be up to hear FM on OSC2).
“I created TANGUY,” notes Teaford, “because I’m passionate about Web Audio, and I wanted to bring my enthusiasm to anyone running Chrome (It sounds awful in Firefox).”
Source is available at GitHub.