The tool was created by Julien Gauthier and is commercially available via the artist's Gumroad.
Art Director at ILM and Blender enthusiast Julien Gauthier has released Architectural Pack, a new set of Geometry Nodes-powered tools designed to help creators with their Blender-made projects. The pack comes with three different geometry node groups and multiple preset examples that you can use and modify at your will.
The pack includes three tools, the first of which can be used to generate fantastic stairs and parapets. You can apply this set of nodes to your cube and start extruding. It will detect when a face is inclined to add stairs. You can also input your own parapet look, corner object, or shader and even add a secondary collection to put on top of the corners to create random variations.
The second system allows you to duplicate an object along a curve. The tool is highly customizable and comes with multiple to give you ideas.
And the last tool included in the pack brings the ability to randomly scatter objects on faces, you can change the density and give random transform to the objects.