Customization of systems is costly, but it is necessary to better meet the needs of multi-various tasks and requirements in the fields such as medical care, education, and so on. A machine translation system, for example, can provide a certain level of multilingual communication support if a human translator is absent; the translation system may need to be customized, however, if it is applied to a new application area. To realize easy customization of multilingual communication systems, we have developed the Language Grid Playground, an online language Web service platform which enables easy customization of various multilingual communication tools. We have established a stepwise process of classifying language services into a layered architecture and developing and accumulating lightweight building blocks that constitute communication tool components. Through this stepwise process, we were able to identify useful components in multilingual communication tools which can be flexibly combined to create new Web services. By implementing several tools and actually accumulating building blocks, we identified useful language service components and developed these components as programs which can be deployed as Web services.