* Klibc library is optimized for correctness and small size. * Klibc is also technically suitable for embedded software in general, and even some full-featured programmes such as the MirBSD Korn Shell. * Klibc is licensed under the full GPL license, which (unlike LGPL) imposes itself on any code linked with it. (This only applies to klibc as a whole due to embedding some Linux kernel derived files; most of the library source code is actually available under a BSD licence from UCB or the Historical Permission Notice and Disclaimer.) This may limit its applicability to commercial embedded software.

musl provides consistent quality and implementation behavior from tiny embedded systems to full-fledged servers. Designed from the ground up for static linking, musl carefully avoids pulling in large amounts of code or data that the application will not use. Dynamic linking is also efficient; by integrating the entire standard library implementation, including threads, math, and even the dynamic linker itself into a single shared object, most of the startup time and memory overhead of dynamic linking have been eliminated. musl features the first post-NPTL implementation of POSIX threads for Linux, and the first aimed at complete conformance and robustness. Thread cancellation has been re-designed to avoid serious race conditions in the original NPTL design. As for efficiency, the whole threads implementation weighs in at around 10-20k depending on target architecture and compiler settings.