Gollum

Gollum is an open-source, self-hosted wiki system built on top of Git. It provides a web interface for managing markup files stored within a git repository, treating the repository contents as the wiki's data source. Users can organize pages into directories and include non-text assets such as images, PDFs, and custom headers or footers for their pages.

The application can be deployed as a Ruby gem, a Docker container, or a Java web application resource. It allows content to be edited through the browser or via a local text editor, with changes becoming visible upon committing to the repository. Gollum is designed to be compatible with GitHub and GitLab wikis, enabling users to clone those wikis and manage them locally on their own hardware.

Key features

• Support for multiple markups including Markdown, AsciiDoc, Creole, and MediaWiki
• Integration of diagrams using Mermaid or PlantUML
• Mathematical notation support via KaTeX or MathJax
• Page annotations using CriticMarkup
• RSS feed for tracking the latest changes
• Ability to view and revert to previous page versions
• Custom CSS and JavaScript injection via repository files
• Support for both MRI Ruby and JRuby

Gollum is built using the Sinatra framework and utilizes different git adapters depending on the environment, such as rugged for MRI and JGit for JRuby. It can be run as a standalone service or alongside a Central Authentication Service (CAS) for single sign-on user support. The software is intended for users who prefer the version control and transparency of Git for their documentation and collaborative notes. It supports various Markdown flavors, including CommonMark, and allows for the installation of additional renderers via gems to expand supported markup languages.

This tool serves as a lightweight bridge between a git repository and a functional web-based wiki, providing a way to maintain documentation in a version-controlled environment while offering a browser-based interface for editing and viewing.