Add a sentence about services

cloud-optimized-netcdf4-hdf5/index.qmd

@@ -5,7 +5,7 @@ author: Aimee Barciauskas, Alexey Shikmonalov, Luis Lopez
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-The following provides guidance on how to assess and create cloud-optimized HDF5 and NetCDF4 files. This assumes one of those formats is a requirement, usually for archival purposes. If these formats are not a requirement, a cloud-native format like [Zarr](../zarr/intro.qmd) should be considered. If HDF5/NetCDF-4 formats _are_ a requirement,  consider zarr-readable chunk indexes such as [kerchunk](../kerchunk/intro.qmd) and [VirtualiZarr](https://virtualizarr.readthedocs.io/en/latest/).
+The following provides guidance on how to assess and create cloud-optimized HDF5 and NetCDF4 files. Cloud-optimized formats provide efficient subsetting without maintaining a service, such as [OpenDAP](https://www.opendap.org), [Hyrax](https://www.opendap.org/software/hyrax-data-server/) or [SlideRule](https://slideruleearth.io/). Often HDF5 and NetCDF-4 formats are a requirement, for archival purposes. If HDF5 and NetCDF-4 formats are not a requirement, a cloud-native format like [Zarr](../zarr/intro.qmd) should be considered. If HDF5/NetCDF-4 formats _are_ a requirement,  consider zarr-readable chunk indexes such as [kerchunk](../kerchunk/intro.qmd) and [VirtualiZarr](https://virtualizarr.readthedocs.io/en/latest/).
 
 ::: {.callout-note}
 You can skip the background and details by jumping to the [checklist](#cloud-optimized-hdfnetcdf-checklist).