Microformats are simply ways of using HTML to format certain data to make it easier for machines to find and use. The two most relevant to edeptive are hCard, for formatting contact details (e.g. name, address, phone numbers) and hCalendar, for formatting event details (what's on, where and when).

edeptive? can store information on companies and individuals (e.g. your company directory) and it can generate pages which display those contact details. When it does so, the contact information is formatted as an hCard so that robots and other tools can make use of them, without having to guess what is and isn't an address. This makes it possible for your users to add contact details directly into their own address books (e.g. Outlook).

One of the edeptive? modules is Events, which stores and displays event information. As with contact details, when edeptive? displays an event it formats the information as an hCalendar so that robots and other tools can find them. This makes it easier for such tools to add the events into your user's calendars (e.g. Outlook) if they choose.