1) make sure you are up to date with OS X El Capitan. (10.11)
2) make sure you have XCode installed, and include the command line utilities with "xcode-select --install" from a terminal.
3) Install Homebrew from here:
http://brew.sh/
4) Install wget with "brew install wget"
5) Install unixodbc with "brew install unixodbc"
6) setup your dev folder structure. dev/ and dev/3rdParty.
7) inside dev/3rdParty download qooxdoo 5.0.1 with:
wget
http://downloads.sourceforge.net/qooxdoo/qooxdoo-5.0.1-sdk.zip
8) unzip qooxdoo