Blockly is a visual programmation editor which uses uses graphical blocks to represent code concepts like variables, logical expressions, loops, and more. It helps students to better understand and apply programming principles without having to worry about the specific syntax of a specific programming language.
Code can then be exported to popular programming languages such as python, javascript, ...
Blocky has been integrated by Cisco in Packet Tracer 8. to ease IoT programming for network students who are not well aware of Javascript or Python programing. The following videos demonstrates the amazing capabilities of this feature.
Video part 1
Video part 2