Kolab is described as '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' and is a Calendar app in the office & productivity category. There are more than 25 alternatives to Kolab for a variety of platforms, including Web-based, Linux, Android, Windows and iPhone apps. The best Kolab alternative is Microsoft 365 Copilot, which is free. Other great apps like Kolab are Google Calendar, Fossify Calendar, Google Workspace and Roundcube.
Brings together calendars, to-dos, productivity apps, and schedulers in one platform. Integrates with major services like Google Calendar, iCloud, Todoist, and video conferencing tools such as Zoom. Offers native scheduling similar to Calendly, enhancing time management efficiency.
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.
Kopano puts an email, video meetings, calendaring, and file sharing solution within one single interface.
grommunio (formerly known as grammm) efficiently combines all requirements of modern, digital communication and collaboration.
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.
IceWarp integrates all communication & collaboration features in one unified solution. Available in cloud or for on-premises deployment, IceWarp is a great tool to share and exchange all information and ideas online, offline or via mobile devices.
Atmail webmail system offers a webmail client, email server platform and mailserver appliance for Linux, Unix and Windows.
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...
OBM is a free messaging and collaboration platform useful for just a couple to many thousands of users with strong support for mobile devices.
Web-based team collaboration suite combining email client, calendar, contact and task tools, CRM, project and file management, file sharing, trouble tickets, Rocket.Chat chat, and Collabora online editing. Offers open source, self-hosted, and SaaS options.
Real-time email, chat, audio/video calls & conferences, file-sharing, and contacts app with a modern and intuitive UI.
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