ROS 1 versus ROS 2

To be clear, this book is all about ROS 2, not ROS 1. You will start learning ROS 2 from zero experience. This section is probably the only time I will be talking that much about ROS 1.

A quick story of ROS, and how we got to ROS 2

ROS 1 (originally called ROS) was first developed in 2007. It quickly gained popularity and grew exponentially in the following years.

In 2014, the ROS 2 project was announced. Simply put, ROS 1 was a bit too limited for industrial applications (lack of real-time support, safety, and so on) and was only used in research/education. To solve this problem, the developers decided to make ROS more “industrial friendly,” as well as make it better, thanks to all the lessons learned from the beginning of ROS.

Now, why create ROS 2 and not just continue ROS with some new changes? Well, the changes were too big, and they would have completely broken compatibility with older versions. Thus, it was decided to create a completely...