This paper describes an implemented software prototype for the Distributed Collaboration and Interaction (DCI) system, which addresses the challenges of helping humans to act as an integrated part of a multi-agent system. Human interaction with agents who act autonomously most of the time, such as a process control agent in a power plant, has received little attention compared to human interaction with agents who provide a direct service to humans, such as information retrieval. This paper describes how liaison agents within the DCI system can support human interaction with agents that are not human-centric by design but must be supervised by or coordinated with humans. Further, the DCI prototype supports notification and planning for humans from the perspective of an organization. It treats humans in this organization as if they were agents with explicitly modeled roles and activities related to software agents in the same system. Planning for humans presents unique challenges because the models represented in traditional planners do not match well with human mental models. The DCI prototype is applied in the domain of NASA advanced life support systems, which are controlled by software agents in an autonomous fashion with occasional human intervention.