these are live examples that javascript is not alien technology and that pretty clever stuff can be done with small effort.
I don't mind the 'X in 30 lines of JavaScript' articles at all, they're nice curiosities. That said, let's not pretend JavaScript is unique in its ability to do a lot in very few lines of code. I've seen more impressive raytracers written in just as few lines of C for example, Perl one-liners that draw a live analog clock on the console, competent Python web services in less than 100 lines of code, etc.