ODA Drawings Explorer (formerly Teigha Viewer) for DWG files. How to install and make it work properly?

ODA Drawings Explorer

To install ODA Drawings Explorer (formerly known as Teigha Viewer, freeware but not free nor open source software):

1. Download ODA Drawings Explorer for Linux 64-bit (DEB) manually or using commands below:

   cd ~/Downloads
   wget -c https://download.opendesign.com/guestfiles/Demo/ODADrawingsExplorer_QT5_lnxX64_7.2dll_22.6.deb
   

2. Install the dependency and then the downloaded DEB package

   sudo apt install qt5-default
   sudo apt install ./ODADrawingsExplorer_QT5_lnxX64_7.2dll_22.6.deb 
   

This will install odadrawingsexplorer package and /usr/bin/ODADrawingsExplorer GUI app.

ODA File Converter

For ODA File Converter (formerly known as Teigha File Converter):

1. Download ODA File Converter for Linux 64-bit (DEB) manually or using commands below:

   cd ~/Downloads
   wget -c https://download.opendesign.com/guestfiles/Demo/ODAFileConverter_QT5_lnxX64_7.2dll_22.6.deb
   

2. Install the package

   sudo apt install ./ODAFileConverter_QT5_lnxX64_7.2dll_22.6.deb
   

Same as above but with it will install odafileconverter and /usr/bin/ODAFileConverter GUI app.

DWG converter on FreeCAD

To install and add the DWG converter to FreeCAD use latest stable FreeCAD from PPA:

sudo add-apt-repository ppa:freecad-maintainers/freecad-stable
sudo apt install freecad

Note: the qt5-default package is not available for Ubuntu 21.04, you have to use some workaround. To get Qt 5.14 on Ubuntu 18.04 LTS and 20.04 LTS you can use this answer.