Gollum — Git-Powered Wiki with Multi-Format Support

Introduction

Gollum is a wiki system built on top of Git, originally created by GitHub for its own wiki feature. Every page is a file in a Git repository, so you get full version control, branching, and merging for free. It runs as a lightweight Ruby web application.

What Gollum Does

• Renders wiki pages from Git-tracked files in Markdown, AsciiDoc, Org, reStructuredText, and other formats
• Provides a web-based WYSIWYG and raw editor with live preview
• Tracks every edit as a Git commit with full diff and blame history
• Supports file uploads, diagrams via Mermaid and PlantUML, and math via MathJax
• Offers full-text search across all pages using a built-in adapter

Architecture Overview

Gollum is a Sinatra-based Ruby application backed by the Rugged library (libgit2 bindings). Each wiki maps to a single Git repository; page reads are Git tree lookups, and saves are commits. The rendering pipeline converts markup to HTML through a chain of filters (macros, tags, sanitization). Because the store is plain Git, you can clone, edit offline, and push changes back.

Self-Hosting & Configuration

• Install via gem install gollum (requires Ruby 3.1+ and CMake for Rugged)
• Run with gollum --host 0.0.0.0 --port 4567 /path/to/repo
• Use --allow-uploads to enable image and file attachments
• Configure authentication through a Rack middleware or reverse proxy (Nginx, Caddy)
• Deploy with Docker: docker run -v wiki:/wiki -p 4567:4567 gollumwiki/gollum

Key Features

• Zero-database architecture — everything lives in Git
• Multi-format markup support with automatic format detection
• Page history, diff view, and revert with standard Git tooling
• Sidebar, header, and footer templates for consistent page layout
• Extensible via custom macros and Rack middleware

Comparison with Similar Tools

• Wiki.js — Full-featured with database, GraphQL API, and built-in auth; heavier to operate
• BookStack — Organized by shelves/books/chapters; MySQL-backed, richer RBAC
• Outline — Collaborative knowledge base with real-time editing; requires PostgreSQL and Redis
• Docmost — Modern collaborative wiki with block editor; needs more infrastructure
• HedgeDoc — Real-time collaborative Markdown; focused on single documents rather than wiki structure

FAQ

Q: Can I use Gollum with an existing Git repository? A: Yes. Point Gollum at any Git repo and it will serve files matching supported markup extensions as wiki pages.

Q: Does Gollum support authentication? A: Gollum itself has no built-in auth. Use OmniAuth middleware, HTTP basic auth via your reverse proxy, or Authelia/Authentik in front.

Q: How do I back up a Gollum wiki? A: The wiki is a Git repo — push it to any remote (GitHub, Gitea, bare server) for backup and redundancy.

Q: Can multiple users edit at the same time? A: Concurrent edits are handled via Git merges. Conflicting changes to the same page will require manual resolution.

Sources

• https://github.com/gollum/gollum
• https://github.com/gollum/gollum/wiki