i didn't saw any dedicated category for FreeCAD software. it is a good free alternative with many capability.

it is completely free and you can download it here: https://www.freecadweb.org/downloads.php

one of its usefull possibility is to visualise and convert all well known files formats

for those interested , below some short basis tutorial

https://www.youtube.com/watch?v=IN0tHR0MKCE

https://www.youtube.com/watch?v=zrSBAsQg8PM

https://www.youtube.com/watch?v=Vs5pq1jfNa4

https://www.youtube.com/watch?v=BgVsRU1nBJo

https://www.youtube.com/watch?v=04MLFzzxq-0

https://www.youtube.com/watch?v=lt__asVyRVs

https://www.youtube.com/watch?v=fL6t_lOnyQ0

https://www.youtube.com/watch?v=L_tuvnViWck