Object-oriented programming (OOP) is one of the most popular paradigms used to build software systems. However, there is currently no object-oriented programming language using the pure idea of OOP. The EO programming language is an object-oriented language developed as a research solution, the purpose of which is to show that industrial programming in pure OOP ideas is practically possible. This work consists in analyzing the EO language, finding the optimally needed collection objects, as well as developing a library of collection objects. In the course of the research, the following tasks were formulated: domain analysis, overview of the basic concepts of the EO language, object analysis in Java, implementation of a library of collection objects, that characteristics objects should have and what tasks they should solve, prototyping in the EO language.