Homelessness Data ExchangeThe Homelessness Data Exchange (HDX - www.hudhdx.info) is an on-line tool designed to allow Homeless Continuums of Care to submit data to the U.S. Department of Housing and Urban Development (HUD). Data gathered by HDX is intended for HUD and community use only. Public data sets are available at the HUD Exchange or by contacting the specific Continuum of Care (CoC).