Our portal.hdfgroup.org site which housed documentation and downloads is currently down.
We are rebuilding the content on a new site. We hope to have the portal.hdfgroup.org URL back working quickly and will be working to return content as quickly as we can. This is an opportunity for us to build back better.
In the meantime if you need to download HDF5, HDF4, or HDFView please visit https://support.hdfgroup.org/downloads/index.html