Allot of work has probably gone into the creation of this comparison chart of Javascript UI libraries. Which is great and appreciated.
Tragically the author didn’t specify the meaning of the X axis. With benchmarks both can be the case. (Here it is apparently shorter is better). The comments on the post do point this out. Oddly the author did not fix the page. Would have taken 1 minute.
It might also be that not having a meaning on the axis’ caters to the biggest audience: People looking for this page might already have a favorite. So, let’s say you embrace YUI (shivers) then you come to this page, look at the long bars and click away just having confirmed that YUI is best. (Firmly ignoring what should have been a give away that protoype does even have longer bars).
People probably roam the Internet looking for ‘information’ that confirms what they were thinking all along. Since the Internet is pretty vast this works better than it ever did in history. There are 22,000 pages about unicorns and postage stamps.