ICSiCalendar

ICSiCalendar is a cross-platform calendar software and API designed to help individuals and organizations manage events, schedules, and reminders. It includes a client application and a server-side component, along with developer SDKs for integrating calendar functionality into other software.

Key features include time zone aware event handling, recurring events, invitations, reminders, and support for importing and exporting calendars in iCalendar (.ics) format. The platform emphasizes offline access, synchronization, and conflict detection to help users stay organized across devices.

ICSiCalendar conforms to the iCalendar standard (RFC 5545) for data interchange and supports CalDAV for server-side synchronization in compatible environments. The data model centers on calendars, events, attendees, and reminders, enabling multi-user collaboration with event sharing and RSVP tracking.

Architecture-wise, it is designed as a modular system with a core calendar engine, platform adapters for web, desktop, and mobile clients, and a server API that exposes REST endpoints. The SDKs provide language bindings for JavaScript, Python, and Java to facilitate integration into diverse applications.

Development and adoption: The project has been developed by ICSiTech as an open-source offering. It has found use in educational settings as well as in small to medium-sized organizations seeking a flexible scheduling solution that can be customized or extended.

See also: iCalendar, CalDAV.