Okay, I need to create a professional wiki-style document about GitHub under the categories of Technology > Software > Open Source. Let me start by understanding the requirements.

First, the structure: H1 for the title, an overview section, several sections with H2 and H3 headings, and maybe references or related documents. The content needs to be accurate, objective, detailed enough, easy to read, and use technical terms with explanations. Also, markdown formatting with proper hierarchy, lists, tables, code blocks if needed. It should be at least 800 characters.

Starting with the title: "GitHub" as H1. Then an overview section explaining what GitHub is, its purpose, maybe a brief history. Next sections could include features, how it works, use cases, and related topics. I need to make sure each section has enough detail but isn't too verbose.

For the overview, I should mention that GitHub is a web-based platform for version control using Git. Founded in 2008 by Tom Preston-Werner, Chris Wanstrath, and P.J. Hyett. Acquired by Microsoft in 2018. It's used for collaborative software development, hosting repositories, code reviews, etc.

Next sections: Features of GitHub. Maybe break it down into version control, collaboration tools, project management, integrations. Each feature can have H3 headings. For example, under features, "Version Control with Git" as an H2, then H3 for repository structure, branching strategies, etc.

How GitHub Works: Explain the workflow—cloning repositories, making changes, committing, pushing, pull requests. Maybe a diagram or table here? But since it's markdown, maybe just describe it step by step.

Use Cases and Applications: Different scenarios where GitHub is used, like open-source projects, enterprise development, personal projects. Mention specific tools like GitHub Actions for CI/CD, GitHub Pages for hosting websites.

Security and Privacy: Discuss security features like two-factor authentication, repository permissions, vulnerability scanning. Maybe mention GitHub's security advisories.

Community and Ecosystem: Talk about the community aspect, how developers contribute, issues and pull requests, documentation. Also, third-party integrations and APIs.

References and Related Documents: Link to official documentation, other resources like Git's website, maybe some case studies or articles.

I need to ensure that technical terms are explained. For example, when mentioning "Git," briefly explain it's a version control system. When talking about pull requests, define them as a way to propose changes.

Check for accuracy: GitHub was founded in 2008, acquired by Microsoft in 2018. Correct. Features like repositories, issues, projects, etc. Make sure the information is up-to-date.

Avoid markdown syntax that's not allowed. Use H1, H2, H3 properly. Maybe use bullet points for features and sections. Code blocks if there are examples, but since it's a general overview, maybe not necessary unless explaining commands.

Check length: 800 characters minimum. The example provided in the user's previous response was around 1500 words, so I need to make sure mine is sufficient. Maybe expand each section with more details.

Also, ensure that the document flows logically from introduction to features, how it works, use cases, security, community, and references. Avoid repetition.

Potential sections:

• Introduction
• Features of GitHub (with sub-sections)
• How GitHub Works
• Use Cases and Applications
• Security and Privacy
• Community and Ecosystem
• References

Each section should have enough content. For example, under "How GitHub Works," explain the workflow step by step. Under "Use Cases," give examples like open-source projects, enterprise use, etc.

Make sure to mention key features like repositories, pull requests, issues tracking, project management tools (like boards), CI/CD with Actions, and integrations with other services.

Also, include information about GitHub's role in the software development lifecycle, collaboration, code review processes, and how it facilitates teamwork.

Check for any recent updates or changes to GitHub's features post-2018 acquisition. For example, new tools like GitHub Copilot or enhanced security features.

Avoid subjective language; keep it factual. Use terms like "enables developers" instead of "is great for."

Now, structure the markdown with proper headings and content. Ensure each H2 has at least a couple of H3 sections if needed. Use lists where appropriate, maybe a table comparing GitHub to other platforms, but that might be too much. Alternatively, mention key features in bullet points.

Finally, proofread for clarity, accuracy, and adherence to the requirements.