People have written about their experience with qooxdoo. Here are some pointers:

• Getting A Little Further Than Hello World With Qooxdoo
  by Atamert Ölçgen

• Using Layouts In qooxdoo (Part 1, Part 2)
  by Atamert Ölçgen

• The Road to qooxdoo (Part I, Part II, Part III)
  by Kenny Tilton

• Tutoriaux en Français (3 x RPC, 5 x Twitter app)
  by Jean-Luc Magnan

• Workshop Javascript-Framework: Qooxdoo
  in magnus.de Magazine by Timo Haberkern

• Da kuckst du: Schicke Webanwendungen entwickeln mit qooxdoo
  in c't Magazine by Andreas Ecker, Fabian Jakobs

• Klassen-Arbeit: Freies JavaScript-Framework qooxdoo
  in iX Magazine by Christian Kirsch, Timo Haberkern