Copyleft is a legal way to use the copyright law in order to maximize rights and express freedom. It impacts our day-to-day work in such a way that companies must know how to deal with open source and free software licenses as they have a high impact on their products.

When building a Linux distribution, there are at least two projects being used: the Linux kernel and a compiler. The most commonly used compiler nowadays is the GNU Compiler Collection (GCC).

The Linux kernel is released under the GPLv2 license, and the GCC is released under the GPLv2, GPLv2.1, and GPLv3 licenses, depending on the project used.

However, a Linux-based system can virtually include all projects available throughout the world, in addition to all applications made by the company for its product. How do we know the number of projects and licenses, and how do we fulfill copyleft compliance requirements?