• New - Faster JavaScript performance via IonMonkey compiler
• New - Support for Retina Display on OS X 10.7 and up
• New - Preliminary support for WebRTC
• CHANGED - Experience better image quality with our new HTML scaling algorithm
• CHANGED - Performance improvements around tab switching
• DEVELOPER - Support for new DOM property window.devicePixelRatio
• DEVELOPER - Improvement in startup time through smart handling of signed extension certificates
• HTML5 - Support for W3C touch events implemented, taking the place of MozTouch events
• FIXED - Disable insecure content loading on HTTPS pages (62178)
• FIXED - Improved responsiveness for users on proxies (769764)

Known Issues

• UNRESOLVED - Certain valid WebGL drawing operations are incorrectly rejected, leaving incomplete rendering in affected pages (see 825205)
• UNRESOLVED - If you try to start Firefox using a locked profile, it will crash (see 573369)
• UNRESOLVED - For some users, scrolling in the main GMail window will be slower than usual (see 579260)
• UNRESOLVED - Windows: The use of Microsoft's System Restore functionality shortly after updating Firefox may prevent future updates (see 730285)
• UNRESOLVED - Starting Firefox with -private flag incorrectly claims you are not in Private Browsing mode (see 802274)
• Unresolved on v18  Resolved in v19
• UNRESOLVED - Plugins stop rendering when the top half of the plugin is scrolled off the top of the page, in HiDPI mode (see 825734)