Kolab2 Installation - Native
From Kolab Wiki
You have the option of installing Kolab Server natively on some selected architectures. Kolab Server has drawn enough interest that it has been transferred from its original OpenPKG installation to natively integrate into other GNU/Linux distributions.
Check out effort from Native Packages.
probably outdated from here on:
The native Kolab Server initiatives
Kolab Server has been integrated natively into several GNU/Linux distributions. The different variants have widely varying status from more or less stable to rough drafts. You will need to check the corresponding documentation in order to determine the state of affairs.