The Yahoo! Developer Blog has a nice post about node.js on how they’re running node.js
A good comment on news ycombinator:
Node.js lets you write server applications in a server container that can handle tens of thousands of concurrent connections in a loosely typed language like Javascript which lets you code faster. It uses the same design as Nginx which is why it can handle so many connections without a huge amount of memory or CPU usage.
If you were to do this on Nginx you’d have to write the module in C.
You can’t do it on Apache because of Apache’s multi-process/thread model.
The fact that you can write a web server in a few lines of easy to understand and maintain Javascript that can handle over 10,000 concurrent connections without breaking a sweat is a breakthrough.
Node.js may do for server applications what Perl did for the Web in the 90’s.
Jason A. Hoffman 