FreeCAD Assembly Workbench
The one to use is Asseembly2 workbench:
Clone the Assembly 2 github repo directly into your '.FreeCAD/Mod/' directory (which also allows easy updates with `git pull` in the future) as follows:
mkdir $HOME/.FreeCAD/Mod cd $HOME/.FreeCAD/Mod git clone https://github.com/hamish2014/FreeCAD_assembly2.git
You will now have access to the 'Assembly 2' workbench the next time you close & restart FreeCAD.