Ben,
there are no application packages released for 5.3.0. The package channel lists all packages of the CVS repository marked as 5.3 or 5.3 compatible. Here is the list of the packages in the channel that you will get, when doing a install/upgrade from repository: https://openacs.org/repository/5-3/
For some time, the channel listed as well - incorrectly - all versions from CVS head.
You can get the packages from the 5.2 channel (see https://openacs.org/repository/5-2/) *** here was a typo before, it said 5-3 ***
via the url (replace YOURHOST with the name:port of you host) http://YOURHOST/acs-admin/install/install?package_type=apm_application&repository_url=http%3a%2f%2fopenacs.org%2frepository%2f5-2%2f
If you are adventuresome, you might replace 5-2 by 5-4 in the URL above to see the packages from head. This is NOT recommended.
The tested packages for the 5.3.* kernel will be released with dotlrn 2.3.0 which is currently in alpha 2 state. The release is a matter of weeks.
