From the title, you might be wondering exactly what GPL is. GPL is a type of open source software licence that stands for General Public Licence.

Open source software licences are of many types, like the GNU General Public Licence, MIT Licence, Apache Licence, etc.

In this article, I will be explaining only about GNU General Public Licence and the benefits and harmful features of having it.

The basic definition of GNU General Public Licence, or simply GPL, is a licence that ensures that everyone has the right to use, study, share , modify the software.

The GPL encourages the use, modification, and sharing of software, but there is a catch.

Whatever you build using GPL code, you have to share it under the same licence or a similar one. That's the cancerous property GPL has.

This simply means that if you have used GPL code in your commercial project, you must also make the source code of your entire project available under the GPL. This is known as the "viral" nature of the GPL.

Here are some real-world examples of successful GPL-licensed commercial projects:

1. WordPress: The popular content management system WordPress is licenced under the GPL, and there are many businesses that sell themes, plugins, and other services for WordPress.

2. Linux: The Linux operating system is also licenced under the GPL, and there are many companies that sell Linux-based software and services.

3. Android: The Android mobile operating system is based on the Linux kernel and is also licenced under the GPL. Many companies sell Android-based devices and apps.

In summary, if you want to build software that everyone can use, modify, and distribute for free, then go for this licence. This licence will ensure that people who use your software for free or commercial use will also follow the same process.