Install the default nodejs of your distribution via your favourite package/ports manager and you are good to go.
Head to the node.js site and download and install the latest version. It is recommended to restart after the installation, as paths may not be up-to-date.
Mac OS X
We strongly encourage you to use homebrew. Make sure you have checked your homebrew installation with brew doctor.
Install node via brew install node.
Make sure you don't sudo anything related to node. If you think you have to, you are doing something wrong and are probably dealing with a broken homebrew/macports installation! If this is the case, the easiest way of resolving this is completely deleting the homebrew (and if present macports) directories and (re)installing homebrew.
The default system's max opened file limit in mac os x is very low (256), in order to use grunt watch, it needs to be increased.
You can either set this in your shell via ulimit -n 8192 to a sensible value or you can set it permanently by adding
limit maxfiles 8192 20480
Grunt & Bower
With npm install -g bower grunt-cli you can install the global npm dependencies needed for grunt and bower.
Installing node dependencies for OX Appsuite Frontend development
Change to the ui directory of your git workdirectory and run npm install.