One feature which is sorely missed by owners of multiple Macs is the ability to easily share their calendars and contacts between their computers. There are third-party software solutions, such as Mark/Space's The Missing Sync, but they cost money. There are also web services that offer calendar and contact synchronization, but they either cost money (such as MobileMe), or they are not completely dependable and compatible (such as Plaxo and Google).
Apple has another solution for you, in addition to MobileMe, and that's to get Mac OS X Server. Among other things, the server edition of OS X has a built-in calendar and contacts server. As of the Snow Leopard version, both are based on the newest standards -- CalDAV for calendars, and CardDAV for contacts. All you need to do from your client computer is to subscribe to the server from within iCal and Address Book, and you are all set for bi-directional sync.
Fortunately enough, these portions of OS X Server are also open-source, and are known as the Darwin Calendar and Contacts Server
. The two servers are still separate projects (written in Python and based on the Twisted framework), and are very much under development.
The CardDAV server was only released in early 2010. Consequently, a lot of the installation, configuration and operation is only half-baked, and it takes some work to get to the point of the famous Apple "it just works" (well, they do want you to buy OS X Server). Nevertheless, once you have everything up and running, this is exactly what you get: the most dependable way to sync your calendars and contacts within a local network or over the internet, for free. You can designate any Mac on your network to be the server, and it will serve itself as well.
To help get this working, I've written up a detailed tutorial
on how to get both CalDAV and CardDAV running on a Mac, thereby turning allowing you to easily sync contacts and calendars through that Mac.
While I've got the author's permission to replicate his how-to here, the reality is that, at over 8,000 words with a slew of associated images, I don't have the time available to reformat the article for displaying in the macosxhints template. So if you're interested in reading about syncing via CalDAV and CardDAV servers, visit the linked site.
To protect this hint, in the event that the original site ever vanishes, I've also created a PDF from the how-to, and placed it on the hints server: CalDAV and CardDAV how-to (1.38MB)
. I'd use the linked site first, though, as it's likely to be updated at some point.]