I’ve written in the past about Spanning Sync, a great little app for synchronizing your iCal calendars on your Mac with Google Calendars. Unfortunately, the app went through some growing pains during its transition to Tiger and its feature set has remained stagnant for quite some time. I’ve never actually paid for a license for Spanning Sync because I disagree with the time-limited $25 fee in principle and the “enternal” $65 fee is just way too much.
So it’s not surprising that a new competitor seems poised to butter Spanning Sync’s bread. BusySync from BusyMac is cheaper and much more feature-rich than Spanning Sync. In its first incarnation, BusySync was just about synchronizing iCal calendars between Macs on a LAN or over the internet. Version 2, released yesterday, adds full synchronization capabilities between iCal and Google Calendar.
The two applications use different models to maintain synchronicity between iCal and Google. Spanning Sync leverages the peer-to-peer philosophy. No calendar on either side of the sync relationship is an authoritative source for event information, both are equal. BusySync, on the other hand, uses a publish-and-subscribe model that established a calendar on one side of the relationship as authoritative.
This makes BusySync a little easier to set up. If you have a calendar in iCal, you just have to publish it to Google and a new calendar will be created on that side of the relationship. Spanning Sync requires that you have one calendar in iCal and one calendar on Google that you relate them to one another.
Both models support full event synchronization, so entries created either in iCal or Google Calendar will appear on the other side of the relationship. However, my guess is that the BusySync model is going to be a lot more robust. From my experience with synchronizing calendar events between mutiple systems, conflicts will always arise. Establishing one data source as being authoritative goes a long way to avoiding conflicts and, when they do occur, resolving them. Reading through the Spanning Sync forums I find that a lot of users have problems with duplicate entries appearing in their calendars when using Spanning Sync, and I would suggest that the peer-to-peer model is partly to blame for this.
That said, I’ve used both applications as Google Calendars sync managers, and have found them both to be excellent. (I didn’t test BusySync’s iCal synchronization capabilities, since I have no need for them.)
Spanning Sync is probably the easier of the two to get started with. Since it only does one thing, and does it well, there are no distractions from other features. And that’s the drawback in BusySync: the interface is a lot more involved and slightly more confusing, since it does offer other features that you may or may not use.
Without a doubt, BusySync is a better value: $25 for a time-unlimited license (with special discount pricing of $19 until May 1, 2008). As I mentioned, I don’t agree with Spanning Sync’s time-dependent licensing model, so I have trouble recommending it. Spanning Sync costs $25 for a one-year license, or $65 for a lifetime license.