# Who's OOO

> Who's OOO is free, open-source leave management for small and mid-size teams. Self-hosted under AGPL-3.0. Tracks vacation, sick days, and team absences with approvals, Slack status sync, iCal feeds, two-factor authentication, and public holidays — without subscription fees or per-seat pricing.

Who's OOO is a Symfony 7.4 / PHP 8.5 web application backed by MySQL 8.4. The marketing homepage lives at [www.whoisooo.app](https://www.whoisooo.app); the application itself is self-hosted — each team runs its own instance, there is no public hosted version. The source code is on [GitHub](https://github.com/igornast/who-is-out-of-office).

- License: AGPL-3.0
- Deployment: Docker, Symfony-friendly PHP hosts (e.g. fortrabbit), self-hosted on your own infrastructure
- Data ownership: all employee data stays on the server you control — relevant for GDPR and regulated industries
- Test coverage: 95%+
- Intended users: teams of ~5 to ~200 who have outgrown spreadsheets but don't want to pay per-seat SaaS pricing

## Key pages

- [Homepage](https://whoisooo.app/): Product overview, features, who it's for
- [Documentation hub](https://whoisooo.app/docs): Index of all setup and configuration guides
- [Blog](https://whoisooo.app/blog): Articles on self-hosted leave management, comparisons, and project updates

## Documentation

### Getting Started

- [Introduction](https://whoisooo.app/docs/introduction): What Who's OOO is, how it works, and what it can do for your team
- [Installation](https://whoisooo.app/docs/installation): Set up Who's OOO on your server using Docker or deploy to fortrabbit

### Configuration

- [Configuration](https://whoisooo.app/docs/configuration): Environment variables for Slack, iCal feeds, and application settings
- [Leave Types](https://whoisooo.app/docs/leave-types): Configure the categories of leave available to your team
- [Public Holidays](https://whoisooo.app/docs/public-holidays): Import and manage public holiday calendars that affect leave request workday calculations

### Administration

- [Roles & Permissions](https://whoisooo.app/docs/roles-permissions): Understand the access control model and manage who can do what
- [User Invitations](https://whoisooo.app/docs/user-invitations): Invite users to the app and walk through the account activation flow

### Integrations

- [Slack Integration](https://whoisooo.app/docs/slack-integration): Connect Who's OOO to Slack for leave request approvals, weekly digests, and personal notifications
- [iCal Feeds](https://whoisooo.app/docs/ical-feeds): Subscribe to a personal calendar feed of approved leave requests

## Blog posts

- [TimeOff.Management vs Who's OOO: Open Source Leave Management Compared](https://whoisooo.app/blog/whos-ooo-vs-timeoff-management): Comparing TimeOff.Management vs Who's OOO? Full open source leave management comparison: stack, Slack sync, LDAP, API, and which self-hosted tool fits your team.
- [Who's OOO 0.3.0: Feed Customization, Org Chart, and Public Holidays](https://whoisooo.app/blog/whos-ooo-0-3-0): A short recap of what shipped in Who's OOO 0.3.0: a customizable iCal feed, a better org chart, public holidays in the request calendar, and an in-app news feed.
- [HR SaaS Vendor Risk: When Your Leave Management Tool Disappears](https://whoisooo.app/blog/hr-saas-vendor-risk): Real stories of HR SaaS tools that shut down, got acquired, or hiked prices, and what they tell you about the cost of depending on a vendor for leave management.
- [Adding Two-Factor Authentication to Who's OOO](https://whoisooo.app/blog/adding-2fa-to-whosooo): How I added optional 2FA to Who's OOO: encrypted TOTP secrets, Argon2id backup codes, rate limiting, and no open-redirect traps.
- [Google Sheets Leave Tracker: A Free Self-Hosted Alternative](https://whoisooo.app/blog/leave-tracker-spreadsheet-alternative): Outgrown your Google Sheets leave tracker? Here's a free self-hosted alternative with approvals, Slack sync, and shared team calendars.
- [Self-Hosted vs SaaS Leave Management: Open Source Tools Compared](https://whoisooo.app/blog/self-hosted-vs-saas-leave-management): Comparing self-hosted leave management to SaaS? See the real cost difference, GDPR implications, and which open source absence tracker fits your team.
- [Why I Built Who's OOO](https://whoisooo.app/blog/why-i-built-whosooo): Every company I worked at tracked leave differently. Spreadsheets, calendar invites, Slack messages that got buried. At some point I got tired of it and built something.

## Categories

- [#comparison](https://whoisooo.app/blog/tag/comparison/) — 3 posts
- [#news](https://whoisooo.app/blog/tag/news/) — 2 posts
- [#tech](https://whoisooo.app/blog/tag/tech/) — 2 posts

## External resources

- [Source code on GitHub](https://github.com/igornast/who-is-out-of-office): Issues, releases, and contribution guidelines
- [Live development on YouTube](https://www.youtube.com/@igor_koneko): The maintainer builds Who's OOO live on stream — open development you can watch and follow to see who is behind the project