To showcase the capabilities of the CheerpJ compiler we have published several demos

OpenAstexViewer

https://cheerpjdemos.leaningtech.com/OpenAstexViewer.html

This demo highlights how complex Java applets with 3D rendering can efficiently and safely run in any browser using CheerpJ.

This specific applet is a visualization tool for protein structures, the source code is available here: https://github.com/openastexviewer/openastexviewer

Swing examples:

https://cheerpjdemos.leaningtech.com/SwingDemo.html

A few selected Java Swing examples to demonstrate how complex Swing GUI apps can be automatically converted to HTML5/JavaScript.

Source: https://docs.oracle.com/javase/tutorial/uiswing/examples/components/index.html

JavaFiddle

https://javafiddle.leaningtech.com/

A playground to compile and run Java programs directly in the browser. Both console and GUI applications are supported. The standard javac compiler is used, since javac is also written in Java the whole compiler runs in the browser, together with the compiled application. Source: [https://javafiddle.leaningtech.com/index.html] (Inspect the page using the devtools)

iText Demo

https://cheerpjdemos.leaningtech.com/iTextDemo.html

Edit PDFs fully client side using the industry standard iText library converted to JavaScript. This demo demonstrates how CheerpJ APIs can be used to instance Java objects and call methods directly from JavaScript.

Source: https://cheerpjdemos.leaningtech.com/itextCheerpJDemo.js