Visual, spatial, and often node-based environments for programming as an alternative way of organizing logic than actually writing lines of code. I've listed some of my favorites and the coolest I've found here.

There are a ton of different names for this kind of programming environment and there doesn't seem to be just one:

Names in Circulation


Modkit

NTK

S4A

Rete.js

Embrio - A visual, real time development tool for the Arduino

XOD

Ardublock

Visuino - Visual Development for Arduino