Science and technology multiply around us.
To an increasing extent, they dictate the languages in which we speak and think.
Either we use those languages, or we remain mute.
This chapter continues our travel throughout the measurement applications software, by focusing the attention on one of the most important paradigms of the last decades: Object-Oriented Programming. The main concepts of Object-Oriented Programming and the related design patterns are presented. Finally, the main concepts of Aspect-Oriented paradigm are illustrated by emphasizing the advantage of its use in measurement applications.