I'm looking for a way to display a shared Exchange calendar in SharePoint 2013. I understand that, OOTB SharePoint will only show the current user's calendar, but I'm assuming that the underlying plumbing to pass a user's credentials and talk to Exchange might already exist and if not, I should be able to use Exchange Managed API to retrieve calendar info and display in a calendar view.
Question is - where to start? I'm fairly new to SP development. For any developers out there, do you have any recommended way of tackling this? I was thinking of adding an option to AggregationCustomize.aspx that called a custom application page to allow you to set up the calendar and then just make it a regular overlay. This approach seems like it would require modification of a _layouts page, which I understand is not recommended. Maybe an app? Any advice or general pointers would be much appreciated.