This service delivers (most of) the datasets held at
GAVO Data Center. In addition to the default (nonstandard)
way of just appending accrefs to the get access URL, there is also a
very simple datalink service here that, for each dataset, essentially
just gives the dataset itself and possibly a preview. More advanced
datalink services might be available.
Some datasets may be embargoed, in which case the access yields a 403.
Credentials for individual files may be obtained by contacting the
site operators.