Truespace (version 3.2)
Truespace is a modeling program developed by the Caligari company. In 2008, Microsoft took over the program, but they did not develop the program anymore. The last version 7.6 became freeware. Since augustus 2012 , the website of Caligari went offline. However, Truespace is still used a lot in Activeworlds, as the file extension of Truespace (.cob) can be used directly in Activeworlds.
There are several versions of the program, TS3.2 was a popular version.
The final version 7.6 was freeware, and has more features , but is more complicated.
Version 3.2 is older and might not be compatible anymore with the current operating system of your computer, then you might try version 7.6.
The Caligari website has gone down, but you can still find the download files in the AWForum, go there to the subforum Artist's Boulevard, and look for the post of 14th april 2019 : Truespace Installer Downloads.

Click upon the buttons below :
Truespace 3.2 - Overview of the Truespace menu
Truespace 3.2 - Making a simple bench in stone.
Truespace 3.2 - Modeling techniques