I've ported the QR Code logic from my pl javascript library into dartlib. I don't have funky animations yet, but:

• The QR Code is generated off-thread using isolates.
• It compiles to Javascript. ~9,000 lines worth.
• The JS version seems to work fine in Chrome, but not Firefox or Safari.

The conversion was pretty straight forward. Types in Dart make debugging this type of code so much easier. Isolates make it easy to keep CPU-intensive tasks (like generating QR codes) from slowing down your UI.

Cool.