Group Office

Group Office is a fully featured groupware platform that helps teams collaborate, manage customers, and run their business. It includes a CRM module for tracking contacts and deals, project management with task lists and time tracking, a groupware email and calendar client, and a document management system. The software also provides an invoicing and billing module, plus a simple website builder for creating public-facing sites.

The platform runs on Linux with PHP and MySQL or MariaDB, and integrates via IMAP, SMTP, CalDAV, CardDAV, and WebDAV. It offers a responsive web interface, mobile apps, and can be extended through modules. Group Office is built on the Yii framework and supports multiple languages. It is developed by Intermesh, a Dutch company, and has been actively maintained since 2009.

Group Office is ideal for small to medium businesses that want an all-in-one collaboration and billing solution without per-user license fees. The community edition is free and open source under AGPLv3, while a hosted version with support is available. For self-hosted users, it provides a cost-effective alternative to proprietary suites like Microsoft 365 or Google Workspace.