Node.js

To list all dependencies and their versions

npm list

To list dependencies of only the current application

npm list --depth=0

To list outdated packages

npm outdated 

To list all global outdated packges

npm -g outdated

To install dependency only for dev

npm install <dependency> --save-dev

To uninstall a dependency

npm uninstall <dependency>

To uninstall a dependency globally

npm uninstall -g <dependency> 

What is n?

n is a version manager for node.js
Once node.js & npm is installed you can install n globally with
npm install -g n 
for mac - sudo npm install -g n

Activate/install specific version of node using n

n <node-version>
for mac - sudo n <node-version>