Please, make a backup of your work before installing a new version of Birdfont.
Windows 10 and later: birdfont-4.12.3-free.exe 64 bit OS
Windows 7 and later: birdfont-4.12.0-free.exe
Windows Vista and later: birdfont-2.13.0.exe
Mac OS 11.0 and later: birdfont-4.12.2-free.dmg
Mac OS 10.15 and later: birdfont-4.12.1-free.dmg
Mac OS 10.12 and later: birdfont-4.12.0-free.dmg
Linux x86_64: birdfont-4.12.2-free.flatpak
The latest version is birdfont-2.29.1.tar.xz (signature). Source code for old versions can be downloaded from the release directory.
The latest stable release for windows is birdfont-4.12.3-free.exe. It works with Windows 10. There is also a package for older versions of Windows available for download, birdfont-4.12.0-free.exe Very old versions of windows is supported in birdfont-2.13.0.exe.
The latest stable release for Mac is birdfont-4.12.2-free.dmg. It works with 11.0 and later versions of Mac OS. Download birdfont-4.12.1-free.dmg if you have Mac OS 10.15 or later. Download birdfont-4.12.0-free.dmg if you have an even older version of Mac OS (10.12 or later).
A flatpak is available for Linux x86_64: birdfont-4.12.2-free.flatpak
Run this if you want to check the signature:
wget https://birdfont.org/birdfont.asc
flatpak install --gpg-file=birdfont.asc birdfont-4.12.2-free.flatpak
Packages for OpenBSD and FreeBSD are available in graphics/birdfont.