Those of you who have used KDE software for a while may remember way, way back when it was announced that KDE would be cooperating with a project called OpenSync to provide PIM data synchronisation to a wide range of devices. The program KitchenSync was brought in as an OpenSync frontend and for a while everything was good - you could sync contacts, events, todos, and notes from KDE 3.5 with your mobile phones and PDAs.
Then the OpenSync project moved away from the stable version 0.22 and started work on a grand new 0.3x branch. They said when they reached 0.40, the project would be stable for end users again. Three years later they are still not ready, with the last release, 0.39, one year ago now. The project still has not been abandoned but things are moving extremely slowly.
Meanwhile KDE moved on as well, to our beloved 4.x series. It was decided to wait for OpenSync 0.40, and then put some effort into porting over the KDE-OpenSync integration - but as KDE release after release went by without OpenSync 0.40 being ready, people got bored of waiting for OpenSync and so KitchenSync was dropped, leaving KDE 4.x users no way of syncing PIM data with mobile devices. Further complicating this is the recent move to akonadi, which adds another layer between your PIM data and where you want it to be - on your mobile device. Compounding this is that all distributions, on the instructions of the OpenSync project, still ship the now-unmaintained and uncared-for OpenSync 0.22 version.
A few technically successful KDE Google SoC projects were undertaken to provide an alternative syncing framework (for example based on SyncML) but they never gained enough polish, or enough device support, to catch anyone's attention.
Now one of my introductions to the F/OSS world was helping a project called SynCE, a framework to talk to Windows Mobile devices from Linux. SynCE had always used OpenSync as the syncing framework and a common question on the SynCE mailing lists was "How can I get my data into KDE?" - and there was no answer. So finally given some free time this summer I decided to do something about it.
In total, I backported the half-finished KitchenSync KDE4 + OpenSync 0.40 port back to OpenSync 0.22 so that it is usable right now. Then I did the same for the KDEPIM plugin - but this only works with KDE SC releases before akonadi was introduced (i.e. < 4.4). Then I wrote a brand-new Akonadi Sync plugin for OpenSync 0.22 - not to be confused with the still-in-development Akonadi / OpenSync 0.40 plugin still available in KDE trunk. I'll do separate release announcements for them all.