musl libc

musl is an implementation of the C standard library built on top of the Linux system call API, including interfaces defined in the base language standard, POSIX, and widely agreed-upon extensions. musl is lightweight, fast, simple, free, and strives to be correct in the sense of standards-conformance and safety.

New to musl libc? Read more about musl or visit the community wiki.

SECURITY ADVISORY: All releases through 1.2.1 are affected by CVE-2020-28928 and should be patched or upgraded to a later version.

musl 1.2 is now available and changes time_t for 32-bit archs to a 64-bit type. Before upgrading from 1.1.x, 32-bit users should read the time64 release notes.

Source Code



Public support for musl is available via the mailing list and #musl on the Libera.Chat IRC network. Subscription details and further private/commercial support options can be found on musl's support page.


Development and maintenance of musl is funded by many generous sponsors pledging through Patreon and GitHub Sponsors. One-time donations can also be accepted via Paypal.

Special thanks goes out to individual project sponsors, who have pledged at the $150/month level or higher:

and to Openwall for infrastructure donations for the project mailing list.

Work on musl has also been sponsored by:

Want to support musl and have your company/organization credited as a sponsor? Contact sponsorship AT musl-libc DOT org.