Addon Communication: VisualHeal uses LibHealComm-4.0 for communicating healing. Ideally all healers in the group should have VisualHeal or another addon that uses LibHealComm-4.0 installed. VisualHeal will continue to function even if some healers don't have it, but it will not be aware of healing cast by these players. VisualHeal also contains a backward compatibility layer so it will be able to communicate with LibHealComm-3.0 users.