We developed a more object oriented wrapper around the (already deprecated) HDF.NET library 3 years ago and have been using it with good success since then. To future proof ourselves we used it via an Interface library.
Because we depended on HDF.NET we were stuck at HDF version 1.8.9 which became increasingly an issue as we had to forego HDF improvements. Recently we wrote a new library using the PInvoke system that has been advocated since then. By conforming to our existing interface library we were able to confirm the new libraries functionality using all our existing Unit Tests and functional tests.
Unfortunately our project was terminated almost exactly at the time that the newer PInvoke lib was completed and so this option remains less proven in production.
We would like to offer both libraries as open source if there is any interest - are there any projects out there that might make use of an object oriented HDF library?