Stack technology for electronic simulation web based [closed]

I would like to know which is the stack technologies used in projects like that www.partsim.com/simulator/#1000, https://www.circuitlab.com/editor/#?id=7pq5wm&from=homepage, and others like that. This apps are desktop application embedded in web? or they are make with javascript? Which framework can I used to resolve front end?. Exist some library with can I make principal board and I can pick and place component?