This repository is the source for the C++ Core Guidelines, an evolving set of rules for writing modern C++ safely and effectively. The primary artifact is a large Markdown document (CppCoreGuidelines.md) that is rendered to HTML via Jekyll and published to isocpp.github.io. The repo also contains supporting tooling: a Python style checker that lints C++ code snippets embedded in the Markdown, a script that splits Markdown into prose and code blocks for validation, a Hunspell dictionary for spell-checking the document, and Node.js-based remark configuration for Markdown linting. CI is provided through GitHub Actions, with a legacy Travis configuration still present.