UIzard is an in-browser web application development tool built on various Javascript Framework. You can add and arrange UI components easily by using Drag & Drop in-browser environment. You can also edit JavaScript Code or Html Code on the in-browser environment without operating other editors. You can preview the result of your works immediately.

UIzard is an open source project, following GPL v2 License. However, it is only a beta version so it can be a little unstable at the moment. You can always see UIzard in action here.

UIzard

Requirements: -
Demo: http://uizard.org/UIzard/uizard.php?action=newProject
License: GPL v2 License