What have we done?

• Display list experiment
• Optimized offsetWidth/height

Loading

• Clean up loading code, for realz
• Page cache cleanup

Page & friends

• Page/Frame/FrameView/FrameLoader disambiguation
• Unify scrolling architecture

Layout & Rendering

• Readonly render tree?
• Ref-counted renderers?
• Remove Widgets
  • subpixel
  • another useless hierarchy
• Removal of continuations

Compositing

• One compositing update per frame
• Compositing post-display lists

Debuggability

• Logging
• Log channels
• Dumping
• lldb macros
• notifyutil -p com.apple.WebKit.showRenderTree

Standards things

• Maintain status on all the CSS Properties
• Event loop
• Event handler attributes
• Intersection observer
• Scroll-linked effects
• Houdini