The current dissertation document presents the development of an open-source Python library designed for Operational Modal Analysis (OMA). The main objective of pyOMA2 package is to provide an open-source, user-friendly software ecosystem whereby researchers and engineers may benefit from easy access to advanced and state-of-the-art OMA techniques. The growing demand for OMA in the built environment, as an essential instrument for structural health monitoring, has underlined the need for easily available computational tools; pyOMA2 attempts to cover this gap by using the Python programming language's versatility and simplicity. This dissertation document begins with a starting overview of the current panorama of OMA methods and the already available tools nowadays, pointing out their constraints in terms of accessibility, cost, and adaptability.