The Package Library is a subscription service that contains common applications that are ready to download and deploy. (See the List)
We test each package to ensure that it installs silently. We keep the packages up to date so that you don't have to.
Access to the Package Library requires a paid subscription (OK, there are a few packages that you can access without a subscription).
Paid subscriptions are only available to pro mode users. During the order process you specify which level, if any, of the Package Library that you want.