Outlook Google Calendar Sync - Offers calendar synchronisation between Outlook and Google, including attendees and reminders.
GO Contact Sync Mod - GO Contact Sync Mod is an open source tool to synchronize your Microsoft Outlook contacts with...
Outlook CalDav Synchronizer - Free Outlook Plugin, which synchronizes events, tasks and contacts between Outlook and Google...
EteSync - Secure, end-to-end encrypted and journaled personal information synchronization.
OutlookDAV - Synchronize between Outlook and CalDAV/CardDAVserver.
DAVx5 - DAVx5 is a CalDAV/CardDAV management and sync app for Android.