Open source software like Koha offers libraries an alternative to proprietary software. It provides libraries with access to a global community of developers that help improve and expand the software. While some libraries may have concerns about open source like lack of support or features, companies like ByWater Solutions provide support, training, and work with libraries to add new features to open source software like Koha. Overall, open source aligns well with library values and can offer advantages over proprietary options.