Here are the features of the Amahi Linux Home Server:

Calendars: The HDA has an iCal calendar server in it, compatible with the Macs and Windows Vista Calendar. It also supports Outlook Free/Busy Sync.
Storage and file sharing: .
Wiki: All about the wiki.
Remote Access: Accessing your network remotely.
Backups: Easy full-disk backup and restore!
HDA Apps: Gallery of application for your HDA.
Theme support

Bugs

Amahi Wiki