This might interest people:
"Teaching-focused digital circuit simulator "
This project is a digital circuit simulator implemented in Javascript. It is designed to simulate circuits synthesized by hardware design tools like Yosys, and it has a companion project yosys2digitaljs, which converts Yosys output files to DigitalJS. It is also intended to be a teaching tool, therefore readability and ease of inspection is one of top concerns for the project.
You can try it out online. The web app is a separate Github project.