Download Ancestor Tree Manager 11.1.1 (for Java 21)

ATM is written in Java and can only be installed and run if the correct Java version is installed on the computer.

Java 21 for a (standard) 64 bit computer can be found at Oracle
Java 21 for a (old-fashioned) 32 bit computer can be found at BellSoft

Different flavors of files are offered for the installation of Java. Select the appropriate platform, then preferably choose an Installer (Windows, macOs) or the Debian Package (Linux).
With Linux and macOS there is a choice of software for a (standard) Intel X64 processor or an ARM processor.

Below are the most commonly used Java installers from Oracle:

Windows Defender or any antivirus software will discourage you to download or install Ancestor Tree Manager. This is a standard response to 'Unknown' software. Perhaps it could be prevented with a Code signing certificate but that is not free. And for free software, that's a bit much to ask. However there is a Checksum available.

*** Follow the installation instructions for the appropriate platform ***

Problems installing Java or Ancestor Tree Manager? Feel free to contact me, maybe I can help.

Checksum on Windows

When installing 7-zip you also get a checksum facility:

Checksum on Linux/macOS

sha256sum <file>