I Analyzed 8 Popular Frameworks — Here's What Their Codebases Are Actually Hiding

GitHub tells you the "primary language" of a repo. That label is... incomplete. I've been building a tool that pulls structured data from any GitHub repo — language breakdown, dependencies, health metrics, CI setup, security signals — and decided to point it at some of the most popular frameworks on the planet. A few things caught me off guard. The Data Framework Stars Open Issues Contributors Hidden Detail Next.js 137.6K 3,298 4,037 13% Rust (Turbopack) Go 132.3K — — 5.4% Assembly (runtime) FastAPI 94.9K 168 886 Only 5 direct dependencies Django 86.7K 405 3,383 Zero Docker config Flask 71.1K 3 862 3 issues. That's it. Express 68.7K 183 373 100% JavaScript Rails 58.2K 1,457 6,906 Most contributors of any framework LangChain — 407 3,631 3,631 contributors in 2 years The Surprises Next.js is 13% Rust Not a typo. Turbopack — the Rust-based bundler — accounts for a significant chunk of the Next.js codebase. GitHub labels it "JavaScript" because that's the plurality language, but the realit