Download musl

Git repository

The latest musl source is always available via the git revision control system. Efforts are made to keep the master branch in a state that not only compiles and works, but that works at least as well or better than the latest release.

The following command can be used to checkout a copy of the musl git repository:

$ git clone git://

Source and revision history are also browsable online via cgit.

Official releases

musl generally follows a time-based release cycle, with versions spaced roughly one to three months apart. Version numbering, however, is based on an evolving roadmap for particular compatibility and feature goals. Releases are timed so as to make fixes for major bugs available in release form as soon as possible while leaving ample time for testing after significant invasive changes.

Beginning with 1.1.7, releases are signed with the project GPG key. Its fingerprint is 8364 8929 0BB6 B70F 99FF DA05 56BC DB59 3020 450F and can be cross-checked against @musllibc on Twitter.

See below for release notes summaries and download links.

Current Versions

Mainline - 1.1.21

This series is actively developed but intended for use in production environments as long as appropriate testing is performed.

musl-1.1.21.tar.gz (sig) - January 21, 2019

This release makes improvements with respect to default thread stack size, including increasing the default from 80k to 128k, increasing the default guard size from 4k to 8k, and allowing the default to be increased via ELF headers so that programs that need larger stacks can be build without source-level changes, using just LDFLAGS. Insufficient stack size for AIO threads on kernels that don't honor the constant MINSIGSTKSZ is also fixed.

The glob core has been rewritten to fix inability to see past searchable-but-unreadable path components, and to avoid excessive stack usage and unnecessary syscalls. The tsearch AVL tree implementation has also been rewritten for better size and performance. The math library adds more native single-instruction implementations for arm, s390x, powerpc, and x86_64.

Various bugs are fixed, including several possible deadlocks, one of which was a new regression in 1.1.20.

Older versions

Earlier versions of musl have been moved to a separate page.