Decker
beyondloom.com/decker/index.html
What Jamie wrote
This probably resonates more with me because I did a number of fairly robust projects in HyperCard when I was in High School. My final project for Humanities was in HyperCard. Decker is visually similar to HyperCard, but is built entirely in the browser and uses Lua for scripting. The choice to use very primitive visuals is a definite nod back to HyperCard.