Groupware

Last reviewed Aug 26, 2026 · 426 words

Most people shopping for self-hosted groupware need a CalDAV server, not an Exchange replacement. If the goal is calendars and contacts that sync to your phone without Google, a process idling at 64 MB solves it completely; the heavyweight suites only earn their complexity when a whole team needs shared calendars, webmail, and Outlook compatibility.

How to choose without overbuying

Three questions settle it. First, sync or suite: Radicale and Baïkal speak CalDAV and CardDAV and nothing else — they store your calendars and contacts and sync them to clients. SOGo layers shared calendars, shared address books, and a full webmail interface on top, at the cost of a hard install and a separate mail server you must already run.

Second, Outlook compatibility. If anyone in the household or office uses Outlook, or wants phone sync with zero extra apps, SOGo is the only option here with Microsoft ActiveSync, and that single feature decides the question for many small businesses.

Third, notice that the scheduling tools filed in this category are a different purchase entirely. Cal.com, Rallly, and Easy!Appointments help other people book time with you — appointment pages and date polls. None of them stores your calendar; they sit in front of one you already have.

Where to start

Baïkal is the sweet spot for individuals and families: PHP, SQLite, 128 MB of RAM, and a web admin panel for creating users and collections. Radicale is the choice when even that feels heavy — plain files on disk, no database, around since 2008, and comfortable in 64 MB on the smallest VPS you can rent. SOGo is for teams of roughly ten and up that genuinely need Exchange-style sharing; it scales well, but expect a day of setup rather than an hour.

You still need client apps

Neither Radicale nor Baïkal ships a calendar you can look at in a browser — that is the most common surprise in this category. On iOS and macOS, CalDAV and CardDAV accounts are added natively in Settings. On Android you want DAVx5 (free on F-Droid, a few euros on the Play Store). On the desktop, Thunderbird handles both protocols. Budget ten minutes per device and the whole family is synced.

First-timer default: Baïkal in Docker behind your reverse proxy. It is the smallest thing with an admin UI, the setup fits in an evening, and if you later outgrow it, your data exports as standard .ics and .vcf files that any successor will import.