I am new to this kind of stuff, but lately I've been hearing a lot about how good Node.js is. Considering how much I love working with jQuery and JavaScript in general, I can't help but wonder how to decide when to use Node.js. The web application I have in mind is something like Bitly - takes some content, archives it.

From all the homework I have been doing in the last few days, I obtained the following information. Node.js

• is a command-line tool that can be run as a regular web server and lets one run JavaScript programs
• utilizes the great V8 JavaScript engine
• is very good when you need to do several things at the same time
• is event-based so all the wonderful Ajax-like stuff can be done on the server side
• lets us share code between the browser and the backend
• lets us talk with MySQL

Some of the sources that I have come across are:

• Diving into Node.js – Introduction and Installation
• Understanding NodeJS
• Node by Example (Archive.is)
• Let’s Make a Web App: NodePad

Considering that Node.js can be run almost out-of-the-box on Amazon's EC2 instances, I am trying to understand what type of problems require Node.js as opposed to any of the mighty kings out there like PHP, Python and Ruby. I understand that it really depends on the expertise one has on a language, but my question falls more into the general category of: When to use a particular framework and what type of problems is it particularly suited for?