1)   MAPILab Groupware Server 1.5.3.2
MAPILab Groupware Server is a cost effective alternative to the traditional methods of Outlook sharing. It allows you to easily share contact details, message folders and more over your network without requiring Microsoft Exchange Server.

 2)   SYNCING.NET 2.0
Sync your Outlook and your files on all your PCs and share them worldwide with colleagues or friends! SYNCING.NET keeps all your data in perfect sync and automatically backed up. It is easy to use and secure - no server required!

 3)   OLfolders 2.8.5
Small office networks - Microsoft Outlook 97 to 2007 - OLfolders allows the real time access and sharing of contacts, calendars, tasks, emails stored on different computers from each workstation simultaneously in a given Outlook network.

 4)   ShareO for Outlook 3.51
Share Outlook folders without server. Microsoft Outlook add-in for synchronizing and sharing Outlook folders, sharing PST, sharing email, sharing calendar without Exchange. Share calendar, share Outlook contacts, sync Outlook contacts, address book.

 5)   QSynchronization 2.5.1
QSynchronization is a Microsoft Office Outlook add-in. It synchronizes uni- or bidirectional your Outlook folders on Outlook notebooks or PDA such as contacts, calendars, appointments, tasks, emails with your central Outlook data.