Nextcloud is a free software (under AGPL 3 and GPL 2) developed in PHP for storing data (e.g. files, calendars, contacts, etc.) on a private server. The user can access the data via a web interface as well as with client applications (smartphone and desktop). Servers and clients can synchronize. Nextcloud enables the user to access a central and consistent database from many end devices and optionally share it with other users. In addition to data storage, Nextcloud offers functionalities for video conferences and various office applications via the web interface. It is a PHP MySQL based web software.
On June 2, 2016, Frank Karlitschek, together with other developers, left his company, which was founded in 2010 under the name ownCloud, and announced “Nextcloud” as a fork. Since then, Nextcloud has been actively developed by Frank Karlitschek, other members of the original developer group and a large community. Nextcloud offers some features that ownCloud does not offer or only offers in its enterprise version.
Features of Nextcloud
Basic functions include:
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- SAML Single Sign-On Authentication (SSO)
- Passwordless authentication (passkeys)
- Two-factor authentication
- User, group and rights management (extensible, e.g. for authentication with LDAP)
- Password Policy
- Brute force protection
- Monitoring (Web/API) interface
- Integration with Windows network shares (SMB/CIFS), external storage with Swift, FTP/SFTP, WebDAV,
- Amazon S3, Google Drive, Microsoft Azure, and Dropbox
- Video conference via Nextcloud Talk
- Screen sharing via Nextcloud Talk
- Encryption of the data on the server as well as encrypted transmission via SSL/TLS
- Share files and folders with other users, groups, or public URLs
- Anonymous uploading (no user account required)
- Conferencing via WebRTC
- Integration of Collabora Online, an online office application based on LibreOffice
- Integration of OnlyOffice
- Viewer for PDF and Microsoft Office files
- Full-text search
- Customizing the Appearance (Theming)
Plugin Ecosystem of Nextcloud
Since the software has a modular structure, it can be expanded with any functionalities using a plug-in system. Through a manufacturer-operated platform, developers can offer their extensions to other users for installation. This platform communicates with the Nextcloud instances via an open protocol. In Nextcloud’s App Store, which can be reached at apps.nextcloud.com, there are already over 250 extensions. With the help of these extensions, the following functionalities can be added, among others:
- Calendar (also as CalDAV), Address Book (also as CardDAV)
- E-mail program
- Feed reader and bookmark management
- Text recognition for images and PDF files, collaboration (comments on files, keywording))
- View activity and implement the requirements of the General Data Protection Regulation (GDPR)
- Music and video playback and listening to Internet radio
- Task planner (to-do lists), creating mind maps, creating diagrams (e.g. network, flowcharts, business processes, UML), Kanban project management
- Integration of content management systems (e.g. Pico-CMS), web analytics (e.g. Piwik/Matomo)
- Editing text files with support for Markdown and WYSIWYG editor for text files including Markdown support
- Evaluation of geodata in GPS Exchange format
- Password management (KeePass integration)
- Weather Forecast, Digital Imaging and Communications in Medicine and Maps (Cartography) Viewer
- Photo gallery or management of cooking recipes
- Basically, there are different apps in different categories, such as Files, Games, Monitoring, Multimedia, Organization, Security, and Communication.
Desktop sync clients are available for macOS, Windows, Linux, BSD, and other Unix-based operating systems. For the popular Linux distributions, there are ready-made DEB/RPM packages. There is an Outlook add-in. This allows the integrated use of Nextcloud for attachments (files or entire folder structures). The add-on module is available in a free and an enterprise version. While the free version is limited in functionality and is aimed at private users, the paid “enterprise version” is intended for use in companies and offers advanced functions, such as protecting links with a password.
There is also an add-on for Mozilla Thunderbird called Filelink to use Nextcloud as a data store. There are software projects that integrate Nextcloud directly as a data store, e.g. the learning platform Moodle, the mobile app “Scanbot” or the groupware solution Zimbra.
