I'm confused, what does this post have to do with Ruby, other than a brief mention about how Ruby's syntax is different from other languages?
project euler stuff is just javascript, might as well run it in the browser.
The post is mostly about convenience. I use javascript all the time. Now I can use it more. I love ruby, I just end up having to relearn it every time I use it because I don't use it often. Node is just the vehicle of that convenience.