jaxlib is the support library for JAX. While JAX itself is a pure Python package, jaxlib contains the binary (C/C++) parts of the library, including Python bindings, the XLA compiler, the PJRT runtime, and a handful of handwritten kernels. For more information, including installation and build instructions, refer to main JAX README: https://github.com/google/jax/.