On macOS you can install and upgrade via Homebrew:
brew install --cask lagrange
Please check MacPorts if you are using macOS 10.12 or older.
Fedora and any RHEL/CentOS Stream 8 and 9 derivatives (RHEL, CentOS Stream, Alma, Rocky) that have the EPEL repos enabled:
sudo dnf install lagrange
On openSUSE Tumbleweed:
sudo zypper install lagrange
The original Gemtext version of this page can be accessed with a Gemini client: gemini://skyjake.fi/lagrange/install.gmi