PigPen had this right... it visualized syntax that you typed. You could technically code with the mouse but that wasn't the intention of the tool. It made it easier to get a gestalt view of things, without hiding the essential details of operations. It was just another window into your code in Eclipse. I think Microsoft's IDE has similar stuff for OO code? But I've never used it.

https://wiki.apache.org/pig/PigPen

I tried to commercialize this technology in 2010, with Cloud Stenography (a joke name): https://github.com/rjurney/Cloud-Stenography https://vimeo.com/6032078

More recently, a company has done some similar stuff, albeit for Spark, in Seahorse: http://seahorse.deepsense.io/