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 1.2.5 are affected by CVE-2025-26519 and should be patched (1, 2) or upgraded.
SECURITY ADVISORY: All releases through 1.2.1 are affected by CVE-2020-28928 and should be patched or upgraded to a later version.
Users of 32-bit systems upgrading from 1.1.x to the 1.2 series
should read the time64 release notes regarding 64-bit
time_t and how it affects compatibility with an existing
environment.
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.