jart/cosmopolitan

Health v2 · maintenance only

Adoption not part of the score

21258 stars · 773 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Cosmopolitan Libc is a C/C++ library and toolchain that makes C a build-once run-anywhere language by producing polyglot executables that run natively on Linux, macOS, Windows, FreeBSD, OpenBSD, NetBSD, and even BIOS. It reconfigures stock GCC and Clang via the cosmocc compiler to output Actually Portable Executables with tiny footprints and native performance.

Use cases

• compile a C program once and run it on Linux, Mac, and Windows without recompiling
• build a single-file self-contained executable with no runtime dependencies
• cross-compile C/C++ projects using autotools for every platform at once
• debug binaries with built-in --strace and --ftrace system call and function tracing
• create tiny high-performance command-line tools that boot from BIOS or EFI
• distribute a CLI tool as one zip polyglot file that runs anywhere

When to choose

• you write C/C++ and want one binary that runs across all major operating systems
• you need minimal-footprint, dependency-free executables
• you want built-in tracing and debugging features in your binaries
• you target exotic environments like BIOS or EFI boot

When to avoid

• your project depends on platform-specific libraries or dynamic linking
• you need a garbage-collected or interpreted language runtime
• your toolchain relies on deep OS integration like systemd or platform GUI frameworks
• you require mature ecosystem support like sanitizers or platform-specific package managers

Facets

library · maturity active

compiler build-tool developer-tools file-system concurrency security developer-tools cross-platform operating-systems compilers programming-languages windows bsd cross-platform cli libc polyglot-binary actually-portable-executable ape cosmocc c c++ build-once-run-anywhere linux macos

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