BeIDSign_1.0.12_macos.dmg: To install BeIDSign app on MacOS use 

Belgium eID-QuickInstaller 5.1.28.6284_1.1.14.exe: To install BeIDSignApp, BeID Sign plugin, virtual smartcard reader and eid-mw
See the Release Notes for more information on Windows version.

BeIDSignPlugin.msi: To install BeID Sign plugin, especially for Acrobat Reader and Adobe Acrobat 32bits on Windows 64 bits

In old_versions you can find older Windows installers.