MRtrix3 can be installed easily on macOS by copy-pasting the following command in a Terminal prompt:
sudo bash -c "$(curl -fsSL https://raw.githubusercontent.com/MRtrix3/macos-installer/master/install)"
The install-script will download the binaries for the latest MRtrix3 release, unpack them to /usr/local/mrtrix3. In addition it will create the appropriate symlinks in /usr/local/bin and /Applications.
Uninstallation is as simple as:
sudo bash -c "$(curl -fsSL https://raw.githubusercontent.com/MRtrix3/macos-installer/master/uninstall)"
./build will download and build MRtrix3 and all its dependencies, create Application bundles for MRView and SHview (including icon sets), and package everything up in a tarball.
./install will download the latest tarball that was generated using build and unpack it to /usr/local/mrtrix3. In addition, it will create the appropriate symlinks in /usr/local/bin and /Applications.
./uninstall will remove the installation at /usr/local/mrtrix3. In addition, it will remove corresponding symlinks in /usr/local/bin and /Applications.
Adding -f to ./(un)install will skip user dialogs.