OnlyOffice Document Server

OnlyOffice is an open-source office suite developed by Ascensio System SIA, offering document editing, spreadsheet management, and presentation tools with a strong focus on collaboration and integration with enterprise platforms. Key features include: Document Editor (rich text editing with styles, tables, headers, footers, footnotes, table of contents, and DOCX native format support with full Microsoft Word compatibility), Spreadsheet Editor (formulas with over 400 functions, pivot tables, charts, conditional formatting, data validation, and XLSX native support), Presentation Editor (slide design with animations, transitions, SmartArt graphics, and PPTX native support), real-time collaboration (co-authoring with multiple users editing simultaneously, cursor tracking, comments, and change tracking via WebRTC and WebSocket), self-hosted document server for integration with Nextcloud, ownCloud, Seafile, SharePoint, Confluence, Alfresco, Chamilo, HumHub, Nuxeo, and Plone via API, OnlyOffice Workspace (complete collaboration platform combining mail, CRM, projects, calendar, chat, and community features), mobile editors (native iOS and Android apps for document editing on mobile devices), PDF forms (fillable PDF form creation and completion with digital signatures), and cross-platform (self-hosted Docker deployment, desktop editors for Windows, macOS, and Linux, and web-based editors).