May I assign differing levels of permission to different groups of users? Does the program understand and use permissions from the operating system?
Yes. There is an extensive permission mechanism built into Calendars for the Web further described here. As of version 1.2.2 Calendars for the Web understands external user validation. If you’ve already identified who a particular user is to your website you may use that information to instruct the program who that person is. Please see this web page for more information.