# qooxdoo

Home » Manual (v2.1.1) » Tooling » Introduction to the SDK

# Introduction to the SDK

While the Hello World tutorial shows you how to use it, this page walks you through the basic structure of the qooxdoo SDK itself.

The SDK, when unpacked to your disk, is simply a structure of files and folders under a common root directory. Main ingredients include the qooxdoo class library, sample and helper applications for the browser, and the scripts, modules and data files of the tool chain.

- In the SDK's root directory there is - besides readme.txt and license.txt - an index.html that gives you an overview over and access to most of the SDK's browser-based applications and components. Just be aware (as mentioned on that page) that all of them need a `generate.py build` first in their respective directories. Only few like the Apiviewer for the framework are shipped pre-built and can be invoked immediately.
- The physical structure of the SDK gives you a high-level view of its files and folders. As you can see there the SDK has four main components represented through the subdirectories application, component, framework and tool. Three of them, application, component and framework contain (either directly or in further subdirectories) qooxdoo applications or libraries that follow the general scheme for a qooxdoo application.
- In each you will find a Manifest.json file which signifies the adherence to the skeleton scheme. They also all contain a generate.py script which offers all or a subset of the standard qooxdoo jobs that you can run on a library, like source, build, test or api.
- The fourth component, tool, comprises the tool chain and its various parts. You shouldn't need to worry about those files since you interact with the tool chain through its executable programs, like generate.py or create-application.py.