What Is GitHub and How Is It Used for Open-Source Projects?
GitHub is a web platform for hosting Git repositories and collaborating on code. For open-source projects like mailcow, it serves as the place where source code lives, releases are published, bugs are reported, and contributions are reviewed. You can use GitHub without writing any code — browsing a project's repository, reading its changelog, or filing a bug report are all legitimate uses. The one thing to keep straight up front: Git is the version-control tool that tracks changes to files, while GitHub is a hosting and collaboration service built around Git. You can use Git without GitHub, and GitHub hosts projects that use Git.
The core concepts you'll actually encounter
| Concept | What it is | Why it matters to you |
|---|---|---|
| Repository ("repo") | A project's folder plus its full change history | The single place to find source, docs, and releases |
| Commit | A saved snapshot of changes with a message | Lets you see what changed and when |
| Branch | A parallel line of development | Where new work happens before it's merged |
| Pull request (PR) | A proposed set of changes, open for review | How outside contributors submit fixes or features |
| Issue | A tracked bug report, question, or task | Where problems get reported and discussed |
| Release | A tagged, packaged version of the project | What you download or upgrade to |
A repository's history is a chain of commits. Branches let people work on changes without disturbing the main line. When a change is ready, it's proposed as a pull request, reviewed, and merged. Issues are the separate track for problems and discussion — they aren't code, but they often drive it.
Finding a project's source, releases, and changelog
For a project like mailcow, the repository is the authoritative source for what's in a given version. A practical path:
- Open the project's repository page. The file listing and README are the front door — the README usually states what the project is and how to install it.
- Check the Releases section (often a link in the sidebar) to see tagged versions. Release notes typically list component version bumps and security fixes. mailcow's own blog, for example, publishes entries such as "Mootember 2026 | Unbound 1.26.1, SOGo 5.12.11 & Redis 7.4.11" and "Mooly 2026 | Postfix 3.10.12, Rspamd 4.1.0 & Nginx 1.30.3," each tied to a dated update release.
- Look for a CHANGELOG file or a changelog link. This is where you confirm exactly which component versions and fixes landed in a release.
- Use the commits view when you need to know when something changed, not just that it changed.
This matters when you're deciding whether to upgrade. A release note that says it "addresses several security-related issues" and "strongly recommend[s] updating" is a different signal than a routine dependency bump.
Reporting a bug or contributing a change
The workflow is the same across most projects:
- Before filing an issue, search existing issues. Duplicates get closed, and the answer may already be there.
- When filing, include what you did, what you expected, and what happened — plus version numbers. For a Docker-based project, that means the image or release version and relevant logs.
- To contribute code, the usual path is: fork the repository, create a branch, make commits, push, then open a pull request against the upstream project. Maintainers review, request changes, and merge.
You don't need commit access to any of this. Forking and pull requests exist precisely so outside contributors can propose changes without direct write access to the main repository.
GitHub vs. Git, in one example
Say you want to fix a typo in a project's documentation. Git, running on your machine, records your edit as a commit and tracks the branch you made it on. GitHub is where you push that branch and open a pull request so the maintainers can see and merge it. Git did the version tracking; GitHub did the hosting and the collaboration. If you only ever browse a project's releases or read its issues, you're using GitHub and never touching Git directly — which is fine.
Where this leaves you
If your goal is to use a project like mailcow, you mainly need the Releases and changelog views to pick and verify a version. If your goal is to report or fix something, you need issues and pull requests. And if you're trying to understand what changed between two versions, commits and release notes are the record — not the marketing page.