For the past few months I've been using this as my wallpaper/desktop background. I'm seldom a fan of any personality or any project, but hey it's LLVM.
I finally found out the source of the picture. It's made by putting the LLVM logo over one of Cocoia's wallpapers.
How did I find out the source? I must have seen the link from some friend's twitter long time ago, but the friend's tweets are locked, and Twitter's search is not really helpful.
So how did I finally find out? Surprisingly, via Get Info in Finder! Essentially, it's the xattr (extended attributes) in the file. Since 10.5, all files downloaded by Safari carry an xattr called com.apple.metadata:kMDItemWhereFroms:. You can use the command line tool xattr to inspect those attributes. The attribute values are in the form of property lists.
I find this a good point to show the importance of file system advance and why metadata matters.
