This is the English reading version of the Dutch news item IngeTrazo: een vrij alternatief voor SketchUp.
IngeTrazo is a free 3D modeller that works like SketchUp: you draw a face and pull it up. It is a mesh modeller, like SketchUp, with faces and edges instead of NURBS surfaces; what that difference means is in the explainer about it. The project comes from Peru, is written in Python and is released under GPL-3.0. In our test it works well.
Blender 3D Architect made this video about IngeTrazo.
Beyond that it is more than a sketchpad. It does solid operations such as union, subtract and split, section planes, groups and components, materials and textures, dimensions and a sheet composer that produces vector PDF. Georeferencing and importing survey points are part of it, as are BIM tags (IfcWall, IfcSlab, IfcColumn) with IFC export of quantities, and a plugin system in which a Python file adds your own tool. It reads .skp files with its own reader; writing back to SketchUp is not possible, you export COLLADA, OBJ or glTF.
The project is young, it has existed since June, and work goes fast: a new version comes out almost every week.
My verdict: for people who want to do simple 3D CAD without frills, SketchUp has always been a good option. Now you can do that with this software too, without limitations.