HDF5 Technical Notes consist of special topics in HDF5 and technical and historical notes or documents. Many of these topics get folded into the documentation. See HDF5 Technical Notes on the old support web site for archived information.
The Query and Indexing in HDF5 feature introduces objects and APIs for querying HDF5 containers and for creating indexes on the contents of HDF5 containers.
The VFD SWMR is a modularized version of the SWMR (Single Writer Multiple Reader) feature that minimizes the maintenance issues inherent to the current implementation of SWMR. It has additional benefits including allowing the HDF5 library to guarantee the maximum time from write to availability of data read, and it may be extendible to NFS and object stores.