Radicale

Radicale is one of the longest-running open-source CalDAV and CardDAV servers, with over 4,500 GitHub stars and an active maintainer team that has been shipping regular releases for more than a decade. It targets the niche of personal and small-team groupware: users who want native calendar and contact sync across all their devices, without paying for and trusting their personal data to a SaaS calendaring service.

Common Use Cases

Privacy-conscious individuals self-host Radicale as a personal calendar and address book, syncing iPhone, Mac, and Linux desktop natively against their own VPS instead of giving Google or Apple a copy of every event and contact. Families share a private Radicale instance to keep household calendars (kids schedules, vacation planning, shared shopping lists in CalDAV-tasks form) on infrastructure under their own control. Small teams use Radicale as the calendar and contact backend for their own Nextcloud, Mailcow, or Roundcube deployment, taking advantage of standard CalDAV federation. Free software advocates and homelab enthusiasts run Radicale as part of their personal cloud stack, often paired with apps like LLDAP for authentication and Mailcow for email — all under their own domain. System administrators deploy Radicale as a tiny appliance on existing VPSes to back up calendars from their primary groupware as a fallback in case the main server goes down.

Key Features

• Standards-compliant CalDAV (RFC 4791) and CardDAV (RFC 6352) protocol implementations
• Native sync with iOS Calendar, macOS Calendar, Android (DAVx5), Thunderbird, Outlook, GNOME Evolution, and KDE Korganizer
• File-based storage as plain iCalendar (.ics) and vCard (.vcf) files — no database required
• htpasswd, LDAP, and dovecot authentication backends
• Multi-user collections with per-user calendars and address books
• Granular access control rules including read-only and read-write sharing
• Browser-based admin UI for inspecting collections and copying client URLs
• Web hooks and import/export for backup and migration workflows
• WebDAV-compliant URLs that integrate with non-CalDAV file managers
• Tiny Python footprint — typical instance uses well under 100 MB RAM

Backup and Portability

Because Radicale stores collections as plain text iCalendar and vCard files on disk, backup and migration are trivial: copy or rsync the storage directory and you have a complete archive of every calendar and contact. There is no database to dump, no schema to migrate, and no proprietary export format. Calendars can be opened in any text editor for inspection or scripted batch edits. This makes Radicale particularly attractive for users who want long-term archival of their personal calendar history independent of any specific software stack.

Why deploy Radicale on Hostinger VPS

Deploying Radicale on a Hostinger VPS gives you a private, always-on calendar and contact sync server under your own domain with no per-account fees, no third-party scanning of personal events, and no ad-targeted profiling of your social graph. Self-hosting also keeps location-tagged events, contact details, and shared calendar invitations on infrastructure you control — important for both individual privacy and any organization subject to GDPR. The lightweight Python codebase uses minimal CPU and memory, so Radicale runs comfortably alongside heavier apps on the same VPS, and persistent volume storage protects your calendar history across container updates and rebuilds. Full root access lets you wire up LDAP authentication, integrate with backup pipelines that pick up the storage directory, and tune the deployment for whatever scale your household, team, or community needs.