For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:B1-Systems:Horde5:rolling/openSUSE_Tumbleweed/isv:B1-Systems:Horde5:rolling.repo
zypper refresh
zypper install horde5-gollem
For openSUSE Leap 42.1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:B1-Systems:Horde5:rolling/openSUSE_Leap_42.1/isv:B1-Systems:Horde5:rolling.repo
zypper refresh
zypper install horde5-gollem
For openSUSE Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:B1-Systems:Horde5:rolling/openSUSE_Factory/isv:B1-Systems:Horde5:rolling.repo
zypper refresh
zypper install horde5-gollem