https://github.com/kanaka/noVNC/wiki/Browser-support
Windows 7 (64-bit)
Browser Status Performance Notes
Chrome 14.0.835.186 Perfect Fast 32-bit. Native WebSockets
Firefox 7.0 Perfect Fast 32-bit. Native WebSockets
Opera 11.51 Perfect Fast 32-bit. WebSocket emulation with web-socket-js
Safari 5.1 Excellent Fast 32-bit. Native WebSockets. Disconnect issues
IE 9.0.8112.16421 Good Fast 32-bit. WebSocket emulation with web-socket-js. Styling issues
Firefox 6.0.2 Fair Slow (note 3) 32-bit. Native WebSockets