Mucc is a small C compiler for Linux that ships as a single 8.5 MB static file. The preprocessor, assembler, linker, archiver, headers and C library (musl, like zig cc does) are all built in, so you can drop it into an empty container, an old distro or a Raspberry Pi and build C with nothing else installed: no gcc, no binutils, no system headers. 

Programs it builds are static, so they run on any x86-64 Linux. There's a native ARM64 build too, and it can cross-compile between the two.

The whole project actually started as a fork of Rui Ueyama's chibicc. I felt more could be done on this design. So now Mucc adds its own assembler and linker, an ARM64 backend, register allocation, the bundled musl, DWARF debug info, C23 support and a reproducible bootstrap chain.

What’s actually working so far 

- C17 by default, C23 with `-std=c23`, plus the GNU extensions real code uses

- Self-hosting: each release is built by the one before it, and a Mucc-built Mucc produces byte-identical output

- Real projects build and pass their own test suites: SQLite, Lua, zlib, jq, Redis and Tcl with the bundled musl; CPython and Git with the system glibc

- Same ABI as gcc, so objects from either link together

- Compiles its own 33k lines in 0.46 s (gcc -O0: 1.22 s, gcc -O2: 5.35 s)

What’s currently not working, it does no optimization beyond register allocation and constant folding, so programs run about as fast as gcc -O0. No C++, Linux only. For performance-critical code, use gcc or clang.

If you've got C code it chokes on, or a use for it I haven't thought of, I'd like to hear it.

GitHub: https://github.com/Dom-Yan/Mucc

Website: https://dom-yan.github.io/Mucc/

Thanks to Rui Ueyama for chibicc, and to Fabrice Bellard, whose TinyCC showed how much a small compiler can do.