Sync Services are no longer being updated since OSX Lion. Maybe soon they won’t be around any more. What are the alternatives to be used now in order to sync contacts?
edit – more clarification: The context I’m asking this in is building a sync application that is able to connect to a synchronization server (using SyncML). This sync application (client) will be installed on the OSX system and is responsible for seeing which contacts have changed on the client (and thus informing the server) and also applying changes from the server to the client side.
Up until this point we have been using Sync Services for keeping track of the changes and syncing the contacts to a centralized spot, but since SS is obsolete, we’re looking for alternatives. Hope the addition helps.
I’m not really sure what you’re after here. Do you want to, say, edit contacts in the system-wide address book and have those edits propagated to other devices? If so, use the address book framework and leave the propagation up to iCloud’s address book support.
Do you want to store (contact) data unique to your application and have that propagated to other devices? Sure sounds like iCloud is what you’re after there, too. It’s true iCloud doesn’t have an API that’ll let you “keep track of changes”. But if that’s important meta to you, why not include it in the data that’s propagated with iCloud? Or am I misunderstanding what you mean by “keep track of changes”?