Mozilla went to London, England yesterday night to give a workshop about Mozilla Add-Ons and show some of the cool new stuff coming in Firefox 4.

Probably the most impressive thing (next to the new Add-Ons Builder based on Bespin) was the upcoming Features of Firefox 4:

• HTML5 Video display
• Painting with Canvas
• Image manipulation with Canvas – pixel testing, face detection with opencivitas
• Green screen technologies in images and video by detecting pixel colours.
• HTML5 embedded inside SVG (yes!)
• SVG as an IMG
• SVG as a CSS background
• SVG filter/mask/clip
• SVG animations
• Inline SVG inside HTML5
• CSS3 (selectors, @font-face, 2D Transforms, Transitions, Shadow, Gradients ,calculations – calc(2em-10px) )
• APIs: Geolocation, Offline (IndexDB, localStorage, AppCache, FileAPI – binary content of a file input, file drag and drop, web workers, websockets)
• Websockets controller running the presentation from the mobile.
• WebGL

They proved some of the points with demos:

CSS3 filters and SVG masking on HTML5 Video: