Elm Debugger - live online
The debugger was conceived and implemented by Laszlo Pandy. He introduced it during his talk at Elm Workshop 2013. Since then it has been adopted by the @elm-lang organization.
Nowadays, the concepts from the debugger live on in elm-reactor, which is part of the elm-platform, and is proving very valuable in everyday use.
You normally shouldn't need to build the debugger from this repo here anymore.
Further development happens in the elm-reactor repo. Please contribute there!