  Autonomous swarms of robots can bring robustness, scalability and
adaptability to safety-critical tasks such as search and rescue but their
application is still very limited. Using semi-autonomous swarms with human
control can bring robot swarms to real-world applications. Human operators can
define goals for the swarm, monitor their performance and interfere with, or
overrule, the decisions and behaviour. We present the ``Human And Robot
Interactive Swarm'' simulator (HARIS) that allows multi-user interaction with a
robot swarm and facilitates qualitative and quantitative user studies through
simulation of robot swarms completing tasks, from package delivery to search
and rescue, with varying levels of human control. In this demonstration, we
showcase the simulator by using it to study the performance gain offered by
maintaining a ``human-in-the-loop'' over a fully autonomous system as an
example. This is illustrated in the context of search and rescue, with an
autonomous allocation of resources to those in need.
