The Qooxdoo compiler is a NodeJS-based application written in Qooxdoo itself. It loads Qooxdoo source code and adds all the required framework components necessary to create an application that is executable in the browser.
No HTML or CSS has to be used and augmented to define the interface. The Qooxdoo developer does not even have to know CSS to style the interface. Clean and easy-to-configure themes for appearance, colors, borders, fonts and icons allow for complete themability.
While being a client-side and server-agnostic solution, the Qooxdoo project includes different communication facilities, and supports low-level XMLHttpRequests (XHR) as well as an RPC API. An abstract transport layer supports queues, timeouts and implementations via XHR, Iframes and Scripts. Like the rest of Qooxdoo, it fully supports event-based programming which greatly simplifies asynchronous communication.
Qooxdoo is not only a library, but also comes with a set of sophisticated tools. Some help with the development workflow, such as the command line interface. Others let you quickly get to know the widgets (such as the widget browser), become fluent in the Qooxdoo API (such as the API Viewer), or to debug or demonstrate code snippets (such as the "Playground").
A versatile web framework wouldn't be complete without a package system which allows modularizing and reusing code. Qooxdoo's package system is based on GitHub repos. Packages can be installed and published very easily with the Qooxdoo CLI.
Qooxdoo was originally developed by one of the world's leading web hosters: 1&1 Internet (now part of United Internet AG). In late 2015, the Qooxdoo framework with all its assets, was turned over to the Qooxdoo association, located in Switzerland. Qooxdoo development has, since then, been lead by a group of dedicated developers congregating on gitter and github.
Contributions are always welcome, either as code, feedback, or donations.