FreeCAD

Install FreeCAD py3lib

You have to use FreeCAD of version 0.18 (0.19 could not work (0.20 it alpha)).

Linux:

1. Install FreeCAD (or just it's libraries, that will be enough):

   $ sudo apt install libfreecad-python3-0.18

Note that in Ubuntu there is a bug in FreeCAD package; so if you are having error messages like libnglib.so: no such file or directory, then to work around this bug, you have to do the following:

$ sudo apt install libnglib-6.2.1804    
$ sudo echo '/usr/lib/x86_64-linux-gnu/netgen' >> /etc/ld.so.conf.d/x86_64-linux-gnu.conf  
$ sudo ldconfig  

2. In Sverchok preferences dialog, in the "FreeCAD python path" field, enter /usr/lib/freecad-python3/lib/ and press the "Set Path" button.
3. Restart Blender.

Windows:

For Blender 2.93 download and install/unzip Freecad with python 3.7.3 libs pylib 3.7
Or for Blender 3.10 download python 3.9 libs pylib 3.9
Or for Blender 3.10 download and install/unzip FreeCAD with python 3.9.12 libs pylib 3.9.12

Add sverchok freecad-python3-lib path:

...\bin   

MacOS

The current version of FreeCAD has a different version of Python (3.8) so you must use conda-forge to retrieve a version compiled against Python 3.7.

Follow the recipe at FreeCAD Web

While it is activated type which freecad and use this path for the sverchok FreeCad lib path in Preferences. Don't forget to press 'Set Path' before closing the dialog. Restart Blender to take effect.