Koha Integrated Library System (ILS) and OPALS (Online Public Access Library System) are both open source solutions that have gained popularity in the library management world. While both systems have their pros and cons, Koha offers several advantages compared to OPALS.

1. Customizability: Koha is more customizable compared to OPALS. Koha provides a wide range of options and plugins that can be used to enhance its functionality, making it a more flexible solution for libraries. This means that libraries can tailor Koha to their specific needs, making it a better fit for their particular workflow and management requirements.

2. Integration with Other Systems: Koha integrates with other systems such as bibliographic databases, online catalogs, and library databases. This integration makes it possible for libraries to provide patrons with access to a wide range of resources, which enhances the overall user experience.

3. Document Management: Koha provides a comprehensive document management system that makes it possible for libraries to manage, store, and retrieve documents easily. This is a critical feature for libraries as it enables them to maintain the preservation of valuable and historical documents.

4. Robust Reporting: Koha provides a robust reporting feature that enables libraries to generate reports on various aspects of their operations, including circulation, patron activity, and resource usage. These reports can be used to make informed decisions about library operations and improve overall efficiency.

5. OPAC: Koha provides a user-friendly online public access catalog (OPAC) that enables patrons to search for and access library resources. The OPAC is designed to be easy to use and is fully customizable, making it possible for libraries to provide patrons with a personalized and intuitive experience.

6. Support: Koha is a widely used open source ILS, which means that it has a large and active user community. This community provides support and resources for libraries that use Koha, making it possible for libraries to resolve any issues or problems quickly and effectively.

In conclusion, Koha offers several advantages compared to OPALS. Its customizability, integration with other systems, robust document management, reporting features, and user-friendly OPAC make it an attractive solution for libraries looking to improve their operations and provide patrons with a better user experience. Additionally, its large and active user community provides a wealth of support and resources for libraries using Koha, making it a more reliable and trustworthy solution compared to OPALS.