Chainguard Libraries provides software language libraries that are rebuilt from source in a SLSA Level 2 build infrastructure to mitigate supply chain attacks at the package build and distribution stages. The product addresses risks from compromised build systems and hijacked package distribution mechanisms. The service delivers libraries for JavaScript, Java JARs, and Python Wheels through malware-resistant registries. It includes patching of critical and high CVEs for older Python libraries, allowing organizations to maintain security while planning version upgrades. Libraries are built with full provenance and can be consumed through common artifact managers, integrating into existing developer workflows. The product supports over 55,000 Java projects and 15,000 Python projects from PyPI. Chainguard Libraries can be used independently or combined with Chainguard Containers or VMs for protection across the software stack. The service provides a standardized source for language dependencies, reducing manual package curation efforts. The product aims to eliminate supply chain risks associated with malware attacks like XZ-Utils, MavenGate, and npm Shai-Hulud by controlling the build and distribution process for open source dependencies.