Dave Yeo has released (6/27/2010) a test build of Firefox
3.7a6pre, which features support for the new "webm" video format, and
Rich Walsh's earlier patches: scrolling should require 25-50% less CPU
usage than previously; less memory use for new tabs; users of Matrox
video drivers should see a normal display; FlashBlock will no longer
show a floating rectangle.
Source: OS/2 Warp News and Rumors.