The Desktop allows your users to run code that creates a GUI window.
View and interact with GUI
Expand to fullscreen to view larger GUIs
Works with every programming language
More information can be found in the project user guide.
If you currently have a content embedded using an iframe, you will need to add the following tags to your iframe code to enable fullscreen mode: allowfullscreen webkitallowfullscreen mozallowfullscreen.