Kolab Community Alternatives

Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more.

A fully fledged, free email server solution, an open source project (GPL v2).

Google's encompassing suite of cloud-based business apps.

Zoho is an all-in-one online office suite.

Microsoft Office is an office suite of desktop applications, servers, and services for the Microsoft Windows and OS X operating systems.

Web-based IMAP email client

Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft.

Open-Xchange Server 6 is the most advanced Linux based Groupware solution f.

An open source mailserver suite.

Organize your schedule and share events with friends without hassle. With Google's free online calendar, it's easy to keep track of life's important events all in one place.

Horde Groupware is a free, enterprise ready, browser based collaboration suite.

Organize your life — it’s about time!