I use a program called sync2 which keeps multiple outlook workstations in sync. The data is copied from workstation to a directory on my server and then from that directory back down to the other workstations. Each workstation has a client that pulls the updated data from the server directory which acts like a centralized database of all the data. It is basically a very simple peer to peer solution because I do NOT have an exchange server but I need to keep the calendar and contacts in sync between multiple computers. I have been using this for a few years using outlook 2007. I'm somewhat happy with the product. There are occasional duplicate entries that I have to clean up but nothing crazy. I'm planning to upgrade to 2013 on one workstation for a week or so and then upgrade the rest of the computers. I fear this will create a sync issue. Every upgrade that I've done in the path with sync2 has resulted in chaos which eventually gets resolved but after some hassle. Any suggestions as to an alternative program that can sync the same outlook calendar and the same contacts between a few local PCs on the same network? I do NOT want to use a cloud solution due to sensitive client data.