ownCloud

Pioneer open-source file sync and sharing platform that spawned the self-hosted cloud movement.

Open source alternative to:

ownCloud is the original open-source file sync and sharing platform that pioneered the concept of self-hosted cloud storage and directly inspired the creation of Nextcloud. It provides a complete solution for storing, syncing, and sharing files across devices with a user experience similar to Google Drive, but on infrastructure you control.

ownCloud offers desktop sync clients for all major operating systems and mobile apps for iOS and Android. Files can be shared with internal and external users with fine-grained permissions. Enterprise features include SSO integration, antivirus scanning, encryption at rest, and audit logging. The ownCloud Infinite Scale (oCIS) project is a modern, cloud-native rewrite of the platform built for scalability.

With over 8,700 GitHub stars and licensed under AGPL-3.0, ownCloud is widely deployed across enterprises and public sector organizations. It is a battle-tested, enterprise-grade alternative to Google Drive for organizations that require compliance, data sovereignty, and professional support.