For 2.0, we should consider changing the default library version bounds (H5Fset_libver_bounds) so the low bound is equal to the 2.0 library version. This will allow users that are trying out HDF5 to see the best performance and efficiency without concern for backward compatibility. Users that need their files to be readable by older versions will need to adjust this setting. This can be justified by incrementing the first version number from 1 to 2.