What kind of software has its source code available for public use, modification, and inspection?

Open-source software is characterized by its source code being available for public access, which allows users to modify, inspect, and enhance the software according to their needs. This model promotes collaboration and sharing, resulting in a community-driven approach where users can contribute to the software's development, report bugs, and improve its functionalities.

The open-source model not only supports transparency but also fosters innovation by allowing anyone with the necessary skills to contribute improvements or adaptations. Many popular software applications, such as Linux and Apache, are examples of open-source projects that have thrived due to widespread community involvement and the free exchange of ideas.

This concept contrasts with commercial, closed-source, and proprietary software, where the source code is typically restricted to the original developers and not available for public modification or inspection. Such restrictions can limit adaptability and community engagement, which are hallmark features of open-source initiatives.