Nextcloud
Google Workspace and Microsoft 365, replaced by a platform you actually control: Nextcloud is the self-hosted digital workspace. Files is the core: file storage and sync across desktop, mobile, and web clients, with sharing, versioning, and collaboration built in. Around it, Talk provides private text chat, audio/video conferencing with screen sharing, SIP integration, and persistent voice rooms; Groupware bundles calendar, contacts, and mail with delegation support; and Office offers two collaborative suites - the Collabora-based option with deep ODF support, and Euro-Office, whose local-processing architecture delivers strong Microsoft Office compatibility and fast browser rendering with reduced server load. The Nextcloud Assistant threads AI through the platform via a context-aware sidebar, Whiteboard covers visual collaboration, Flow handles automation, and an app ecosystem of hundreds of extensions adds everything from Kanban boards to end-to-end encryption. Hub 26 brings a lighter UI with a unified app switcher and Nextcloud Governance for organizations under strict regulatory requirements. This is the flagship of data sovereignty: your files, chats, calendars, and documents live on your server, under your jurisdiction, with GDPR compliance by architecture rather than by contract.
Collabora Office
Real LibreOffice document engineering in the browser: Collabora Online is built by the company employing much of the former SUSE LibreOffice team - not a reimplementation. This deployment runs CODE (Collabora Online Development Edition), the collabora/code server that renders and edits documents entirely server-side while browsers get high-fidelity WYSIWYG output, so layout and formatting survive round-trips that break lesser converters. Four editors ship in one container: Writer for text documents (comments, track changes with comparison and restoration, form handling), Calc for spreadsheets (advanced formulas, macros, pivot tables, per-user sheet views, server-enforced cell protection), Impress for presentations, and Draw for Visio-class diagrams. Format compatibility spans DOCX, XLSX, PPTX, the ODF family, PDF, and dozens more - including Visio and Publisher import. Real-time collaborative editing supports multiple simultaneous editors with visible cursors and commenting. The architectural point: documents are processed on your server and never leave it, which is why Collabora is the engine behind Nextcloud Office and integrates with ownCloud, Seafile, and any WOPI-speaking host - or embeds in your own application via the SDK. An admin console monitors sessions and memory. For organizations that need Google Docs-style collaboration with actual data sovereignty, this is the reference open-source answer.