Software is a fundamental pillar of modern scientific research, and it is essential to properly archive and reference the source code of software used in all research activities.

In this presentation, we will show how to use the Software Heritage framework to transparently archive all software source code and how to obtain and use the intrinsic identifiers, specially designed for software source code, which are necessary to reference the source code in a way that facilitates long-term reproducibility. We will also show how to describe the source code for a better understanding of the software and to allow discovery of the software on search engines. Finally, we will discuss the challenges when it comes to citing software to give credit to authors in the academic ecosystem.