The Medical & Public Health Information Sharing Environment (MPHISE) is a public/private sector initiative that facilitates the open sharing of medical and public health information across organizational boundaries. The mission of MPHISE is to identify innovative approaches to enhancing situational awareness by harnessing the power of social networks and other mediums, with a goal of enabling community resilience on a global level. MPHISE Chat provides an instant messaging capability for registered MPHISE users.