The best open source alternative to Outline is Affine. If that doesn't suit you, we've compiled a ranked list of other open source Outline alternatives to help you find a suitable replacement. Other interesting open source alternatives to Outline are: AppFlowy, Docmost, and XWiki.
Outline alternatives are mainly Collaborative Notes & Wikis but may also be Wiki Software or Internal Knowledge Bases. Browse these if you want a narrower list of alternatives or looking for a specific functionality of Outline.
All-in-one workspace for note-taking, whiteboarding, and task management with real-time collaboration and local-first architecture.

Affine is a powerful, open-source platform that revolutionizes the way teams and individuals create, organize, and share knowledge. With its innovative approach to collaborative work, Affine combines the best features of note-taking, whiteboarding, and task management into a seamless, intuitive interface.
Key benefits of Affine include:
Affine's unique blend of features makes it an ideal choice for researchers, project managers, designers, and anyone looking to enhance their productivity and creativity. Experience the future of collaborative knowledge work with Affine.
Looking for open source alternatives to other popular services? Check out other posts in the alternatives series and openalternative.co, a directory of open source software with filters for tags and alternatives for easy browsing and discovery.
An open-source alternative to Notion, offering powerful note-taking, task management, and database features in a customizable interface.

AppFlowy is a versatile, open-source productivity tool that combines the best features of note-taking apps and project management software. It provides a flexible workspace where you can organize your thoughts, tasks, and projects with ease.
Key benefits of AppFlowy include:
AppFlowy combines the flexibility of a note-taking app with the structure of a project management tool, allowing you to capture ideas, plan projects, and organize information all in one place. Whether you're a student, professional, or creative, AppFlowy adapts to your needs, helping you stay organized and productive.
A feature-rich wiki platform with real-time collaboration, rich-text editing, advanced permissions, and support for diagrams, translations, and file management.

Docmost transforms team documentation with its powerful collaborative features. The real-time rich-text editor supports simultaneous editing with integrated tools for diagrams (Mermaid, Draw.io, Excalidraw), tables, math equations, and embedded content.
Organization is seamless with nested pages and dedicated spaces for different teams or projects. The robust permissions system with group management ensures precise access control. Content discovery is efficient through Postgres-powered full-text search.
Notable features include:
The platform combines security, flexibility, and ease of use while avoiding vendor lock-in through open standards. Perfect for companies seeking a self-hosted solution for knowledge management, technical documentation, and team collaboration.
XWiki is a flexible, feature-rich wiki software that helps organizations structure and share knowledge efficiently.

XWiki is an enterprise-grade, open-source platform for knowledge management and collaboration. It offers a unique "Structured Wiki" concept, combining the flexibility of wikis with powerful organization features.
Key benefits include:
Structured Knowledge: XWiki goes beyond traditional wikis by allowing users to create structured content, making information easier to organize and find.
Customization: The platform is highly adaptable, supporting custom applications and workflows to meet specific organizational needs.
Collaboration Tools: XWiki provides robust features for team collaboration, including real-time editing, comments, and version control.
Security and Access Control: Granular permissions and access controls ensure that sensitive information remains protected.
Integration: XWiki can integrate with various third-party tools and systems, enhancing its functionality and fitting into existing workflows.
Open Source: As an open-source solution, XWiki offers transparency, community support, and freedom from vendor lock-in.
Scalability: XWiki is designed to handle large amounts of data and users, making it suitable for organizations of all sizes.
Multiple Deployment Options: Available as a cloud service or for on-premises installation, providing flexibility in deployment.
XWiki is trusted by over 800 teams worldwide, including major organizations like Amazon, SNCF, and CNFPT. It's particularly well-suited for creating knowledge bases, managing procedures, building intranets, and developing custom collaborative applications.
Whether you're looking for a standard solution or a custom-tailored platform, XWiki offers the tools and services to streamline your organization's knowledge sharing and collaboration processes.