Calendar apps
Calendars and time-blocking tools.
39 products
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Green, secure, ad-free email with calendar, address book and notes
Open source
T
Turn ON privacy with encrypted email, calendar and contacts
Free planOpen source
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Groupware that runs anywhere, built on tools you can trust.
Free planOpen source
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Native desktop email client for Mac, Windows, and Linux
Free planOpen source
C
Meet the Citadel System. Easy to install. Easy to use. 100% open source. No compromises.
Open source
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Contacts, calendars & tasks for teams.
Free planOpen source
S
Full-Time Open-Sourcerer & App Maker
Free planOpen source
S
An Open Source Webmail for businesses and communities
Free planOpen source
R
Find the best time to meet with a group poll
Free planOpen source
M
Free, GPL web application using PHP and MySQL for booking meeting rooms or other resources
Open source
M
The weatherman without the man — hyperlocal, automated weather forecasts.
Free planOpen source
R
Free and Open-Source CalDAV and CardDAV Server
Open source
D
A research poll and scheduling service operated by TU Dresden's Chair of Data Protection.
Free planOpen source
S
Private, encrypted, secure email with 10 GB free
Free planOpen source
O
The open platform for business communication.
Open source
B
La messagerie collaborative souveraine et ouverte
Open source
D
CalDAV, CardDAV, and WebDAV for Android.
Free planOpen source
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The open source CardDAV, CalDAV and WebDAV server
Free planOpen source
K
Home of WebCalendar, an open-source PHP calendar and scheduling system, plus related tools
Open source
D
A CalDAV Store.
Open source
M
Event listing site for IndieWeb community events
Open source
O
Private, encrypted calendar in the cloud
Free planOpen source
B
Run your own email service for yourself, your organization, or others as an all-in-one web
Open source
K
Stop double-booking yourself. Sync Google Calendar with Outlook & iCloud so all calendars,
Free planOpen source
S
Hybrid workplace software for desk booking, room reservation and office coordination
Free planOpen source
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Decentralized platform for owning and controlling your data
Free planOpen source
T
Software for digital collaboration in companies and organizations, combining groupware and
Open source
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A smarter way to organize your academic life.
Free planOpen source
O
Take notes, plan tasks, track habits.
Free planOpen source
M
Online platforms to create, share and find events.
Free planOpen source
I
IT documentation, ticketing and billing for small MSPs.
Free planOpen source
T
Task manager and life management system with MCP support for AI agents
Free planOpen source
D
A minimalist day planner with time-blocking and task management
Open source
H
Open source scheduling
Open source
T
Everything at home
Open source
T
Your cloud, your rules
Free planOpen source
C
A time zone conversion app for cross-timezone collaboration
Free planOpen source
T
Web App: Online Timer Countdown + Online Alarm Clock + Online Stopwatch
Open source
C
a text-based calendar and scheduling application for the command line
Free planOpen source