ITK-SNAP (and c3d)

Download the tarball from itksnap.org and move it into ~/installs:

mv ~/Downloads/itksnap-4.2.2-20241202-Linux-x86_64.tar.gz ~/installs/
cd ~/installs
tar xvf itksnap-4.2.2-20241202-Linux-x86_64.tar.gz

Add aliases to .bashrc pointing to the itksnap and c3d binaries inside the extracted folder. A symlink does not work here — ITK-SNAP resolves resources relative to the binary location, so use alias.