UC2 is an open-source modular toolbox for making hardware projects based on functional optical blocks. It creates a bridge between education and science by offering an alternative to the standard tools, a generic toolbox that can be used for both fields. The same basic hardware is meant to be used for teaching photonics and its applications in an interactive way and the students could later use the same system in their own work for prototyping. As a community-driven collaborative project, UC2 benefits from the experience of its early adopters and from its attractiveness for project-based courses. It is a collective effort of many researchers and students. This thesis shows the contributions of the author to the project. In this work, we present the development and testing of the hardware for the educational applications. The key aspects of open-source hardware design are evaluated and summarized into a decision matrix defining the boundary conditions of the development. Special importance is given to improving accessibility of the toolbox by providing comprehensive documentation and lowering the entry barrier. Four different educational kits, in summary called “TheBOX”, were developed, with the MiniBOX being at the stage of a production-ready prototype, optimized for mass production. The BOXes are comprehensive toolkits aimed at a specific education level or demonstration of certain experiments. These present a low-cost alternative to the commercially available systems. Additionally to the advantage in price, they offer a lower entry level and create an inviting environment for science education. They were developed in close contact with the users and the improvements were based on iteratively acquired feedback. The system was tested in many workshops and courses and provided tools for student projects.