Musl

musl was designed from scratch to allow efficient static linking and to have realtime-quality robustness by avoiding race conditions, internal failures on resource exhaustion, and various other bad worst-case behaviors present in existing implementations. The dynamic runtime is a single file with stable ABI allowing race-free updates and the static linking support allows an application to be deployed as a single portable binary without significant size overhead. It claims compatibility with the POSIX 2008 specification and the C11 standard. It also implements most of the widely used non-standard Linux, BSD, and glibc functions. There is partial ABI compatibility with the part of glibc required by Linux Standard Base. Version 1.2.0 has support for (no longer current) Unicode 12.1.0 (while still having full UTF-8 support, more conformant/strict than glibc), and version 1.2.1 "features the new 'mallocng' malloc implementation, replacing musl's original dlmalloc-like allocator that suffered from fundamental design problems." ==Use==

Linux distributions which use musl as their standard C library (some use only musl) include but are not limited to: • Alpine Linux • Dragora 3 • Gentoo Linux (glibc by default, musl can be chosen at install time) • OpenWrt • postmarketOS • Sabotage • Adélie Linux • Morpheus Linux • Chimera Linux • Void Linux (but not for IA-32) • KISS Linux A modified version of musl is available for userspace code written for the seL4 microkernel, requiring users to implement the parts of the Linux system call interface that the subset of musl they wish to use depends on. A modified musl wrapper is also utilized written for OpenHarmony distributed operating systems within its userspace for its standard system devices; while it primarily targets a Linux kernel, it employs a Kernel Abstraction Layer (KAL) to map extended POSIX system calls when running on non-Linux kernels of kernel agnostic core system, such as microkernel-based HarmonyOS's HongMeng Kernel Linux ABI compliant shim for POSIX-like functionalities. For binaries that have been linked against glibc, gcompat and glibmus-hq can be used to execute them on musl-based distros. ==See also==