libcso

libcso is a portable, open-source implementation of the C standard library designed for use on a wide range of platforms, from embedded systems to general-purpose operating systems. It provides the core runtime facilities that C programs depend on, including basic I/O, memory management, string manipulation, and standard utilities.

The project emphasizes a small footprint, deterministic performance, and clean API compatibility with conventional C library interfaces. It is designed to be a drop-in replacement in environments where existing standard libraries are too large or lack portability features required by specific platforms or toolchains.

Internally, libcso is modular, separating components such as input/output, memory management, string and byte handling, time, and error reporting. The implementation combines portable C with optional architecture-specific optimizations in assembly to meet performance and startup requirements on constrained devices.

API compatibility and portability are central goals: libcso provides a POSIX- and ISO C-compatible API, with careful attention to errno handling, locale support, and thread safety where available. It ships with compatibility shims to ease porting of code that targets glibc, musl, or uClibc, helping bridge differences between environments.

Build and integration are supported through a portable build system and documentation that guide how to link against libcso during application development. Applications typically link with the library during the linking stage and configure runtime paths in a platform-appropriate manner.

Development and availability: libcso is released as open-source software with a public repository and issue tracker. The project is maintained by a community of contributors and sponsors, with ongoing work spanning core runtime code and platform-specific porting layers to broaden architecture support.