What is the suggested way to install brew, node.js, io.js, nvm, npm on OS X?

Question

1. Using homebrew install nvm:

   brew update
   brew install nvm
   source $(brew --prefix nvm)/nvm.sh
   

   Add the last command to the .profile, .bashrc or .zshrc file to not run it again on every terminal start. So for example to add it to the .profile run:

   echo "source $(brew --prefix nvm)/nvm.sh" >> ~/.profile
   

   If you have trouble with installing nvm using brew you can install it manually (see here)

2. Using nvm install node or iojs (you can install any version you want):

   nvm install 0.10
   # or
   nvm install iojs-1.2.0
   

3. npm is shipping with node (or iojs), so it will be available after installing node (or iojs). You may want to upgrade it to the latest version:

   $ npm install -g npm@latest
   

   UPD Previous version was npm update -g npm. Thanks to @Metallica for pointing to the correct way (look at the comment bellow).

4. Using npm install ionic:

   npm install -g ionic
   

5. What about ngCordova: you can install it using npm or bower. I don't know what variant is more fit for you, it depends on the package manager you want to use for the client side. So I'll describe them both:

   1. Using npm: Go to your project folder and install ng-cordova in it:

      npm install --save ng-cordova
      

   2. Using bower: Install bower:

       npm install -g bower
      

      And then go to your project folder and install ngCordova in it:

       bower install --save ngCordova
      

PS

1. Some commands may require superuser privilege
2. Short variant of npm install some_module is npm i some_module

2019 update: Use NVM to install node, not Homebrew

In most of the answers , recommended way to install nvm is to use Homebrew

Do not do that

At Github Page for nvm it is clearly called out:

Homebrew installation is not supported. If you have issues with homebrew-installed nvm, please brew uninstall it, and install it using the instructions below, before filing an issue.

Use the following method instead

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash

The script clones the nvm repository to ~/.nvm and adds the source line to your profile (~/.bash_profile, ~/.zshrc, ~/.profile, or ~/.bashrc).

And then use nvm to install node. For example to install latest LTS version do:

nvm install v8.11.1

Clean and hassle free. It would mark this as your default node version as well so you should be all set

I'm using n (Node version management)

You can install it in two ways

brew install n

or

npm install -g n

You can switch between different version of node and io. Here's an example from my current env when I call n without params:

$ n

  io/3.3.1
  node/0.12.7
  node/4.0.0
  node/5.0.0
ο node/5.10.1 

I'm super late to this but I didn't like the other answers

Installing Homebrew

For brew run

"$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Installing node & npm

You SHOULD NOT use brew to install node and npm.

I've seen a few places suggested that you should use Homebrew to install Node (like alexpods answer and in this Team Treehouse blog Post) but installing this way you're more prone to run into issues as npm and brew are both package managers and you should have a package manager manage another package manager this leads to problems, like this bug offical npm issues Error: Refusing to delete: /usr/local/bin/npm or this Can't uninstall npm module on OSX

You can read more on the topic in DanHerbert's post Fixing npm On Mac OS X for Homebrew Users, where he goes on to say

Also, using the Homebrew installation of npm will require you to use sudo when installing global packages. Since one of the core ideas behind Homebrew is that apps can be installed without giving them root access, this is a bad idea.

For Everything else

I'd use npm; but you really should just follow the install instruction for each modules following the directions on there website as they will be more aware of any issue or bug they have than anyone else

If you have previously installed node using brew, then you will have a bunch of extra files that you should clean up before installing node "the right way". Plus, I had to add a few settings to my startup script to make things work smoothly.

I wrote a script to make this easy.

# filename:  install-nvm-npm-node
# author:    Lex Sheehan
# purpose:   To cleanly install NVM, NODE and NPM
# dependencies:  brew

NOW=$(date +%x\ %H:%M:%S)
CR=$'\n'
REV=$(tput rev)
OFF=$(tput sgr0)
BACKUP_DIR=$HOME/backups/nvm-npm-bower-caches/$NOW
MY_NAME=$(basename $0)
NODE_VER_TO_INSTALL=$1
if [ "$NODE_VER_TO_INSTALL" == "" ]; then
    NODE_VER_TO_INSTALL=v0.12.2
fi
if [ "`echo "$NODE_VER_TO_INSTALL" | cut -c1-1`" != "v" ]; then
    echo """$CR""Usage:   $ $MY_NAME <NODE_VERSION_TO_INSALL>"
    echo "Example: $ $MY_NAME v0.12.1"
    echo "Example: $ $MY_NAME $CR"
    exit 1
fi
echo """$CR""First, run:  $ brew update"
echo "Likely, you'll need to do what it suggests."
echo "Likely, you'll need to run: $ brew update$CR"
echo "To install latest node version, run the following command to get the latest version:  $ nvm ls-remote"
echo "... and pass the version number you want as the only param to $MY_NAME. $CR"
echo "Are you ready to install the latest version of nvm and npm and node version $NODE_VER_TO_INSTALL ?$CR"
echo "Press CTL+C to exit --or-- Enter to continue..."
read x

echo """$REV""Uninstalling nvm...$CR$OFF"
# Making backups, but in all likelyhood you'll just reinstall them (and won't need these backups)
if [ ! -d "$BACKUP_DIR" ]; then 
    echo "Creating directory to store $HOME/.nvm .npm and .bower cache backups: $BACKUP_DIR"
    mkdir -p $BACKUP_DIR
fi 
set -x
mv $HOME/.nvm   $BACKUP_DIR  2>/dev/null
mv $HOME/.npm   $BACKUP_DIR  2>/dev/null
mv $HOME/.bower $BACKUP_DIR  2>/dev/null
{ set +x; } &>/dev/null

echo "$REV""$CR""Uninstalling node...$CR$OFF"
echo "Enter your password to remove user some node-related /usr/local directories"
set -x
sudo rm -rf /usr/local/lib/node_modules
rm -rf /usr/local/lib/node
rm -rf /usr/local/include/node
rm -rf /usr/local/include/node_modules
rm /usr/local/bin/npm
rm /usr/local/lib/dtrace/node.d
rm -rf $HOME/.node
rm -rf $HOME/.node-gyp
rm /opt/local/bin/node
rm /opt/local/include/node
rm -rf /opt/local/lib/node_modules
rm -rf /usr/local/Cellar/nvm
brew uninstall node 2>/dev/null
{ set +x; } &>/dev/null

echo "$REV""$CR""Installing nvm...$CR$OFF"

echo "++brew install nvm"
brew install nvm 
echo '$(brew --prefix nvm)/nvm.sh'
source $(brew --prefix nvm)/nvm.sh

echo "$REV""$CR""Insert the following line in your startup script (ex: $HOME/.bashrc):$CR$OFF"
echo "export NVM_DIR=\"\$(brew --prefix nvm)\"; [ -s \"\$NVM_DIR/nvm.sh\" ] && . \"\$NVM_DIR/nvm.sh\"$CR"
NVM_DIR="$(brew --prefix nvm)"

echo """$CR""Using nvm install node...$CR"
echo "++ nvm install $NODE_VER_TO_INSTALL"
nvm install $NODE_VER_TO_INSTALL
NODE_BINARY_PATH="`find /usr/local/Cellar/nvm -name node -type d|head -n 1`/$NODE_VER_TO_INSTALL/bin"
echo "$REV""$CR""Insert the following line in your startup script (ex: $HOME/.bashrc) and then restart your shell:$CR$OFF"
echo "export PATH=\$PATH:$NODE_BINARY_PATH:$HOME/.node/bin"

echo """$CR""Upgrading npm...$CR"
echo '++ install -g npm@latest'
npm install -g npm@latest
{ set +x; } &>/dev/null
echo "$REV""$CR""Insert following line in your $HOME/.npmrc file:$OFF"
echo """$CR""prefix=$HOME/.node$CR"
echo "Now, all is likley well if you can run the following without errors:  npm install -g grunt-cli$CR"
echo "Other recommended global installs: bower, gulp, yo, node-inspector$CR"

I wrote a short article here that details why this is "the right way".

If you need to install iojs, do so using nvm like this:

nvm install iojs-v1.7.1

To install brew, just see its home page.

See alexpods answer for the rest.

You should install node.js with nvm, because that way you do not have to provide superuser privileges when installing global packages (you can simply execute "npm install -g packagename" without prepending 'sudo').

Brew is fantastic for other things, however. I tend to be biased towards Bower whenever I have the option to install something with Bower.