Nextcloud

Nextcloud is Germany's most widely deployed open-source collaboration platform, letting organisations run their own private cloud for file sync, video calls, email, and document editing on their own servers. With 400,000+ active deployments reaching tens of millions of users, it is the definitive European alternative to Microsoft 365 and Google Workspace.

The platform combines Nextcloud Files (storage and sync), Nextcloud Talk (chat and video), Nextcloud Groupware (calendar and contacts), and Nextcloud Office (real-time document editing) in a single installation. A REST API and 300+ marketplace apps extend it with LDAP, SAML, SharePoint, and hundreds of third-party integrations.

Key benefits:

• File sync and share across Windows, macOS, Linux, iOS, and Android clients
• Nextcloud Talk — end-to-end encrypted video calls and chat with no external service
• Nextcloud Office — real-time collaborative document, spreadsheet, and presentation editing
• Built-in AI assistant running locally with no data leaving your infrastructure
• 300+ marketplace apps for CRM, project management, e-signing, and more
• Full self-hosting on bare metal, VMs, Docker, or Kubernetes
• Enterprise edition with professional support, compliance tooling, and SLA guarantees

Developed and maintained by Nextcloud GmbH in Stuttgart, Germany, all data stays on infrastructure you control — no third-party cloud involved. The platform is GDPR-native, supports HIPAA-capable configurations, and is used by major EU governments, universities, and public institutions that mandate on-premises data sovereignty.

Trusted by Siemens, the German Government, and thousands of public sector organisations across Europe, with 20,000+ GitHub stars and an active global community.