SOGo, formerly Scalable OpenGroupware.org, is an open source collaborative software (groupware) server with a focus on simplicity and scalability.

SOGo provides collaboration for Mozilla Thunderbird, Microsoft Outlook, Apple Calendar, and BlackBerry client users. Its features include the ability to share calendars, address books, and email using an open source, cross-platform environment. The Funambol middleware and the Funambol SOGo Connector allow SyncML clients to synchronize contacts, events, and tasks.

SOGo supports standard groupware capabilities including CalDAV, CalDAV auto-scheduling, CardDAV, WebDAV Sync, WebDAV ACLs, and iCalendar.

Microsoft Outlook support is provided through an OpenChange storage provider to remove the MAPI dependency for sharing address books, calendars, and emails. Native connectivity to Microsoft Outlook allows SOGo to emulate a Microsoft Exchange server to Outlook clients.

SOGo uses existing services including Microsoft Active Directory, OpenLDAP, SQL, and IMAP. Usage of industry services contributes to scalability. It is accessible through its web interface, desktop clients, or mobile devices.

The web interface uses an AJAX interface and is available in several languages. The look and feel of version 2 mimics Mozilla Thunderbird and provides browser drag and drop capabilities for contacts, events, and mail messages. Single sign-on security capabilities are available by using CAS, WebAuth, or Kerberos. Version 3 is based on AngularJS and Angular Material and provides a fully responsive interface.

Supported desktop clients are Mozilla Thunderbird with the Lightning extension, Apple iCal, and Microsoft Outlook. The SOGo Connector and Integrator extensions for Thunderbird provide improved functionality.

Mobile devices are generally handled through the Microsoft Exchange ActiveSync (EAS) protocol. Devices such Apple's iPhone are handled natively by SOGo as iOS supports CalDAV and CardDAV. Other devices can access the web interface, which is responsive since release 3.0.0.