Many of them seem to require the alpha or beta of Opera. Most of them don't seem to work for me in Firefox or Chrome.

I wish they would explain what parts of each demo is HTML5 and how it works.

Yeah this was just a soft-launch for MWC. We're planning a proper launch soon with more context for the user, proper feature detection, categories, etc.

The goal is to get something decent on all browsers--and we'll open the repo on github for those who want to help us get there.

Ironically the few I bothered to click didn't work in Opera 12 (OperaNext on Linux).

The "Rock Piano" keys get stuck by simply clicking a key, holding, and moving the cursor outside the key. A bit finicky :)

That's a common problem, a key just can't register a mouse button release outside of itself.

Could it check if it is still in a pressed state? There would be a lag, but it wouldn't be broken. I guess.

I imagine there's several ways to do it, it's a matter of figuring out which one is the most efficient for the situation at hand.

For instance, you could log what key was pressed with its own mouse event, then detect a generic mouse release event not tied to the key, look up the log that recorded what key was pressed, and then react accordingly to that. I wouldn't think it would be the best method for a multi-touch device though.

Great demos. I didn't know Chrome had landed webcam support. What a great way to start the morning

Clock and Color Picker both appear to be broken for me...

Of the ones that work: Cool

Nice showcase. The color picker demo seems to be broken.