API Automate GitLab via a simple and powerful API.
CI
GitLab as OAuth2 authentication service provider. It allows you to login to other applications from GitLab.
GitLab Basics Find step by step how to start working on your commandline and on GitLab.
Importing to GitLab.
Markdown GitLab's advanced formatting system.
Migrating from SVN Convert a SVN repository to Git and GitLab
Permissions Learn what each role in a project (external/guest/reporter/developer/master/owner) can do.
Profile Settings
Project Services Integrate a project with external services, such as CI and chat.
Public access Learn how you can allow public and internal access to projects.
SSH Setup your ssh keys and deploy keys for secure access to your projects.
Webhooks Let GitLab notify you when new code has been pushed to your project.
Workflow Using GitLab functionality and importing projects from GitHub and SVN.

Administrator documentation

Custom git hooks Custom git hooks (on the filesystem) for when webhooks aren't enough.
Install Requirements, directory structures and installation from source.
Restart GitLab Learn how to restart GitLab and its components
Integration How to integrate with systems such as JIRA, Redmine, LDAP and Twitter.
Issue closing Customize how to close an issue from commit messages.
Libravatar Use Libravatar for user avatars.
Log system Log system.
Environment Variables to configure GitLab.
Operations Keeping GitLab up and running
Raketasks Backups, maintenance, automatic webhook setup and the importing of projects.
Security Learn what you can do to further secure your GitLab instance.
System hooks Notifications when users, projects and keys are changed.
Update Update guides to upgrade your installation.
Welcome message Add a custom welcome message to the sign-in page.
Reply by email Allow users to comment on issues and merge requests by replying to notification emails.
Migrate GitLab CI to CE/EE Follow this guide to migrate your existing GitLab CI data to GitLab CE/EE.
Git LFS configuration
Housekeeping Keep your Git repository tidy and fast.
GitLab Performance Monitoring Configure GitLab and InfluxDB for measuring performance metrics

Contributor documentation

Documentation styleguide Use this styleguide if you are contributing to documentation.
Development Explains the architecture and the guidelines for shell commands.
Legal Contributor license agreements.
Release How to make the monthly and security releases.