Guides
Run it, review it, understand it.
Practical guides to running other people's code: trying a GitHub project without installing it, keeping untrusted code away from your machine, reviewing pull requests running, and finding your way around a new codebase.
All guides
- How to run a GitHub project on your computer, language by languageClone it, check its root files, install the pinned runtime and dependencies, set up .env and start it. Commands and fixes for Node, Python, Go, Rust, Ruby, PHP.Running code
· 11 min - How to run a GitHub project without downloading it: 8 options comparedgithub.dev can't run code. Codespaces, CodeSandbox, StackBlitz, Replit, Binder, Colab and pyrovue can: what each does, its free tier and which to pick in 2026.Running code
· 8 min - Python circular imports: what actually happens and how to fix themA Python circular import fails because the module is in sys.modules before its code runs. See the exact errors, why import a works, and fixes ranked best first.Reading code
· 11 min - How to understand a new codebase: a method for day one and week oneUnderstand a new codebase in a week: run it, find the entry points, trace one request, map imports and hotspots, then read the tests and git history.Reading code
· 10 min - Is it safe to run code from GitHub? What runs and how to checkNot automatically. GitHub hosts code but doesn't review it. See what runs when you install a repo, real attacks on developers, and how to check and isolate it.Security
· 11 min - How to test a pull request: check it out, run it and merge it safelyCheck out a pull request with gh pr checkout or git fetch, run the tests and the app, test the merge result, and keep untrusted PR code away from your secrets.Code review
· 9 min - What are preview environments? A guide to ephemeral environmentsPreview environments are temporary copies of your app for each pull request. How they differ from staging, how to build them, costs, pitfalls and fork security.Code review
· 11 min - What is a cloud development environment? CDEs explained for 2026A cloud development environment runs your dev setup on a remote container or VM. How CDEs work, Codespaces, Coder, Ona and others compared, and how to choose.Tools
· 10 min - How to add a live demo to your GitHub README, with the exact MarkdownAdd a live demo to a GitHub README with one line of Markdown: a GIF or video, GitHub Pages, deploy buttons, Codespaces, Binder, Colab or a Run on pyrovue badge.Tools
· 10 min - What happened to Gitpod: from cloud IDE to Ona and OpenAIGitpod was a cloud dev environment opened from a link. It became Ona in 2025, closed Gitpod Classic on 15 October 2025 and was bought by OpenAI in 2026.Tools
· 10 min
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