FreeCAD - An open-source parametric 3D modeler
VirtuallyShow.com - VirtuallyShow.com is an online affordable and feature-packed virtual tour service that allows you to create your residential and commercial real estate virtual tours in just a minute.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Immoviewer - Immoviewer is a software solution that combines Automated Real-Estate Video Content creation with simple and scalable 3D 360 tours.
Onshape - Onshape is the first full-cloud 3D CAD system. It runs in a web browser and on any mobile device.
RICOH360 Tours - With no professional equipment or expertise, RICOH360 Tours will let you introduce and share real estate property, facilities, etc., with remotely located customers using means such as a website or through web conferencing.