Gimp is a photo editing application. This is covered in Photo Editing and Compositing.
Unity is a robust game development platform. This is covered in Game Development with Unity.
Create content for film, tv and games with Blender or Maya. Covered in 3D Object Modeling and 3D Animation.
Studio One is a complete studio. This is covered in Music Production Technology.
Hitfilm is a video editor and compositor all in one. This is covered in Video Editing and Compositing.