Apps similar to Kolab include Microsoft 365 Copilot, which has a free version. Other options are Google Calendar, Fossify Calendar, Google Workspace and Roundcube. Calendar Apps like Kolab are a crowded field, with more than 50 alternatives for the web, Linux, Android, self-hosting and Windows.
Exchange business-class email helps increase user productivity while protecting your data. Get it as a hosted service or run it on your servers.
United States
Right Calendar app is a versatile scheduling tool that offers unparalleled flexibility to its users. One of its standout features is that it is built on an open-source platform. This not only ensures transparency but also allows for constant updates and bug fixes from a...
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.
Germany
EU
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.
United States
Kopano puts an email, video meetings, calendaring, and file sharing solution within one single interface.
NetherlandsEU
grommunio (formerly known as grammm) efficiently combines all requirements of modern, digital communication and collaboration.
GermanyEU
This app is tailored for families, couples, friends, and groups, providing end-to-end encryption for secure data, seamless calendar creation, syncing, private chats, and widgets for easy access, ensuring you never miss an event.
United Kingdom
All-in-one European business email and collaboration platform — email, chat, video conferencing, and office suite in one app. Cloud or self-hosted.
CzechiaEU
Is a collaboration suite (messaging and groupware). It is designed to run on open source operating systems such as Linux or BSD. In order to modernize the Citadel platform for the Internet, the Citadel/UX developers added functionality such as shared calendars, instant...
NexMail is an open-source, modern webmail client designed for self-hosted email servers. Enjoy a clean, intuitive interface with powerful features for managing your emails efficiently.
Pakistan
Atmail webmail system offers a webmail client, email server platform and mailserver appliance for Linux, Unix and Windows.
Australia
OBM is a free messaging and collaboration platform useful for just a couple to many thousands of users with strong support for mobile devices.
