A complete set of Platform Invoke (P/Invoke) declarations for the core HDF5 C-API is supported and maintained by The HDF Group, and is available in two forms:
A Visual Studio Solution on GitHub that includes the declarations and unit tests
A NuGet package that includes an "Any CPU" target assembly plus the unmanaged dependencies
This set, HDF.PInvoke, is based on the HDF5 1.8.16 API, and is currently being updated to include the HDF5 1.10.0 API. HDF.PInvoke gives .NET developers CLS-compliant, thread-safe, "C-equivalent" control over HDF5 from .NET languages. It isn’t and is not intended as a "high-level" .NET interface for HDF5.
In 2007-2008, The HDF Group released its first set of HDF5 .NET wrappers, HDF5DotNet. The project was sponsored by Agilent and Boeing. This version was tested with HDF5 1.8.9. HDF5DotNet, written in C++/CLI, wraps a subset of the HDF5 library API in a .NET assembly. Although unsupported and unmaintained it is available and frozen at the November 2012 level. People are strongly encouraged to use the P/Invoke version in place of HDF5DotNet.
See HDF5Mathematica for user-contributed HDF5 Mathematica Wrappers and Introductory Tutorial Examples. The included examples use P/Invoke.
Agilent and Boeing sponsored the first set of HDF5 .NET wrappers that were available in 2007-2008.