SeaMonkey 2.15

- SeaMonkey can be set as default client/browser on Mac and Linux now
- The new IonMonkey compiler improves JavaScript performance
- Preliminary support for WebRTC has been added
- Image quality has been improved through a new HTML scaling algorithm
- CSS3 Flexbox has been implemented
- Support for new DOM property window.devicePixelRatio has been added
- Support for @supports has been added (disabled for now)
- Startup time has been improved through smart handling of signed extension certificates
- HTML5: Support for W3C touch events has been implemented, taking the place of MozTouch events
- Insecure content loading has been disabled on HTTPS pages
- Responsiveness for users on proxies has been improved
- Fixed several stability issues