When exploring the framework source, the following overview will give you an idea about the file structure of qooxdoo:

• application - sample applications (for end users)
  
  
  • demobrowser - for browsing a large number of demos (online)
  • feedreader - a sample rich internet application (online)
  • portal - a showcase for low-level features, i.e. without widgets (online)
  • playground - an interactive playground without the need to install qooxdoo (online)

• component - helper applications (used internally)
  
  
  • apiviewer - API reference (for generate.py api) (online)
  • skeleton - blue print for custom applications (for create-application.py)
  • testrunner - unit testing framework (for generate.py test / test-source) (online)

• framework - main frontend part of the framework
  
  
  • source
    • class - JavaScript classes
    • resource
      • qx - resources need to be namespaced, here it is qx
        • decoration - images for the decorations, Modern and Classic
        • icon - icon themes that come with qooxdoo, Oxygen and Tango
        • static - other common resources like blank.gif
      • source - contains original resources
    • translation - language-specific data as po files

• tool - tool chain of the framework
  
  
  • bin - various scripts are located here, most importantly generator.py
  • data - lots of data to be used by different tools, e.g. for localization, migration, etc.
  • pylib - Python modules used by the platform-independent tool chain