First one is the emerging topics histogram. I followed my own advice and vertically centered the stacked histogram. Additionally, I never liked those sharp edges, so now I do not only “fade out” tags visually, but also fade them in, resulting in a much more organic picture, and largely improved readability of the chart. New color scheme: old tags are cold, freshly introduced ones in warm color. This is all very much inspired by the fabulous last.fm charts by Lee Byron — thanks!

new interactive version here

and some pix: