Node.js runs javascript through a V8 runtime- essentially, javascript out of the browser. In our case, it serves web requests, builds client-side assets, and runs tests. [[Most of the code is shared|Isomorphism]] between the server and the browser.
reddit-mobile in production using 4.2.x, the long-term stable release.
The easiest way, if you're on OSX, is to use homebrew -
install, and then brew install node. There is documentation for other OSes
on the Node.js website.
NPM, or "Node Package Manager", is used to install,
update, remove, and create node.js pacakges. By default, it installs all
packages to your project directory in the node_modules folder - not a global
directory. (To install something globally, use npm install -g packagename).
The packages for a project are installed running npm install from that
project's root, or wherever the package.json file is. package.json is a
manifest file that describes all of the dependencies, and some other meta
information, about a project or package.
Sometimes, you may need to modify a dependency. Rather than modifying the
dependency within node_modules, it's better to clone the module somewhere
useful, symlink it to the global module directory with npm link, and then
delete the project's local copy from node_modules. If a module isn't found
in the local directory, node will look it up in the global directory (you will
need to restart your server / build process to see changes.)