Could you guys please answer Gerrit7's question!
From what I understand the answer is YES: in Mavericks there is no longer a way to sync any i-device except through the cloud.
I use BusyCal and Missing Sync, and both companies have confirmed that syncing in Mavericks (using standard software) can only be done with a cloud service.
You can look at
https://support.markspace.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticl eid=615
and at
https://support.busymac.com/help/10983-upgrading-to-busycal-2-5
Speaking to support of BusyMac, I obtained the information that for calendars it is still possible to run a calDAV server under your own control, and sync through that.
For contacts, apps, notes and the like the only way is the cloud, and I suspect only Apple's iCloud.
I fully agree with Gerrit7 that this is NOT acceptable. I want control over my data. The argument that iCloud is secure is NOT an answer to his question as he clearly stated that was not an option. It is not for me either: I will not go around with a leash around my neck.
I will probably set up a calDAV server on my home LAN's linux server, so I can still do it off-net.
For the other data I will have these options:
(1) switch to linux everywhere (but what a chore...)
(2) stay with Snow Leopard or Mountain Lion (the latter being a pest too) but that is fragile in the longer term
(3) write my own sync software, but this will also mean I have to write my own apps for my mobile devices.
Solution 3 is a real chore, and the resulting software would not be sharable since it would not pass the App Store requirements. I would have to run it for myself only. It can be done though, relatively easily, using a combination of Applescript and LiveCode.