Polynomial systems are essential to understand numerical approximations in applications. This article describes the design and structure of the PHC software package, a robust tool for computing numerical approximations to all isolated complex solutions. The package's versatility stems from its ability to operate in multiple modes, guided by menus and oriented toward files. Exploiting structure in a polynomial system allows the software to use root-counting methods among its tools. The package offers a black-box solver and reports on its performance on a test problems database. Developed on four different machine architectures, the software ensures portability through the gnu-ada compiler. Researchers can use the tool to count roots and solve different black-box problems.
This article, appearing in ACM Transactions on Mathematical Software, fits the journal's focus on significant algorithms and software packages in mathematical software. By detailing the structure and design of the PHC package for solving polynomial systems, the paper contributes to the journal's objective of promoting high-quality mathematical software and related research.