The Data Access Protocol (DAP) and related client-server software have emerged as important standards for Earth science data system infrastructure. The deployment of different DAP-enabled servers has improved access to data in many formats from many sources. HDF5 has been embraced as an important data format for Earth science as exemplified by these adopters: HDF-EOS5, which is built on top of HDF5, is the primary data format for data from the Aura satellite. HDF5 is being used as the data format for the real time data products produced from the tri-agency National Polar Orbiting Environmental Satellite System (NPOESS). Finally, the next generation of netCDF, netCDF-4, is built on top of HDF5. Many widely used DAP visualization clients are using netCDF DAP client library to access data via DAP. However, some HDF data cannot be accessed properly because of restrictions enforced by such approach. We will demonstrate a prototype of a new OPeNDAP client library that can access HDF5 data and HDF5 specific objects via HDF5-OPeNDAP server and DAP. We will also demonstrate how the Grid Analysis and Display System(GrADS) can be adapted to use this prototyped OPeNDAP client library to visualize HDF-EOS5 swath and grid data.