The topic of ontology modularization corresponds to a variety of tasks including the design of modular ontologies and the modularization of existing ontologies. In a previous deliverable, we defined the formal foundation for the support of some of these activities within NeOn, in the form of a formalism and a set of operators for defining, creating, combining and manipulating modules. In this document, we describe the implementation of a set of plugins for the NeOn Toolkit, particularly focusing on the task of specifying modules, combining modules, partitioning ontologies into a set of modules and extracting modules from ontologies. This set of interoperable plugins provide an interactive environment for ontology engineers to cope with ontology modularization. Other aspects related to ontology modularization, namely methodologies and reasoning for modular ontologies, will be treated in different deliverables and are therefore only briefly considered in this document.