Roundcube AlternativesOnly apps categorised as Calendar Apps

The best Calendar alternative to Roundcube is Kolab, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Roundcube and three of them are Calendar Apps so hopefully you can find a suitable replacement. Other interesting Calendar App alternatives to Roundcube are Zimbra Collaboration Suite and OX App Suite.

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Roundcube alternatives page was last updated May 14, 2025

Kolab
43 likes
Kolab provides a FOSS communication & collaboration solution that can be completely self-hosted. Take back control of your data and access it via the webinterface, or existing mobile & desktop clients.
Cost / License
Freemium
Open Source
Application type
Calendar
Origin
Switzerland
Platforms
Linux
Online
Self-Hosted
Is Kolab a good alternative to Roundcube?
Zimbra Collaboration Suite
35 likes
Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more. With the most innovative web application available today, Zimbra boosts the productivity of users on any desktop and dramatically reduces TCO compared to legacy platform vendors.
46 Zimbra Collaboration Suite alternatives
Cost / License
Paid
Proprietary
Application types
Mail Server
Calendar
Origin
United States
Platforms
Linux
Online
Self-Hosted
Is this a good alternative to Roundcube?
OX App Suite
16 likes
The OX App Suite by Open-Xchange is web-based platform offering a suite of apps like an email client, calendar, contacts magement, cloud storage with synchronization and productivity apps for word processing, spreadsheets and presentations.
20 OX App Suite alternatives
Cost / License
Free
Open Source
Application types
WebMail Provider
Mail Server
Origin
Germany
EU
Platforms
Linux
Online
Self-Hosted
Software as a Service (SaaS)
+6
Is OX App Suite a good alternative to Roundcube?

3 of 3 Roundcube alternatives