The C programming language includes a very limited standard library in comparison to other modern programming languages. This is a collection of common computer science data structures and algorithms which may be used in C projects.
The project is structured in a modular way, such that it is possible to
trivially copy any module (pair of .c and .h files) into a project without
dealing with the usual hassle of library dependencies. However, the project
does also build as a library named libcalg if that's what you want.
The code is licensed under the ISC license, a permissive license that is functionally identical to the MIT or BSD licenses. As such, it may legitimately be reused in any project, whether proprietary or open source.