2D Map Level Design

Hello Everyone …!! ,

I would like to ask if anyone knows which program mr.Patrick Haslow used to create the 2D Map In his Course. ( Creating a Level Blockout for Game Development.) It Looks really awsome and clean. He was also to choose each things in his map to explain what it does and etc.

Yours sincerely,
Panagiotis Chatzilabrou aka iLLatus.