Nextcloud

Nextcloud is a suite of client-server software for creating and using file hosting services. It provides functionality similar to Dropbox, Office 365, or Google Drive, but with the added flexibility of being hosted either in the cloud or on-premises. It features a modern, on-premises content collaboration platform with real-time document editing, video chat, and groupware on mobile, desktop, and web. Developed by Nextcloud GmbH, it is written in PHP and JavaScript.