This paper presents AgentService, a framework for developing Multiagent Systems (MAS). The key features introduced with AgentService are a flexible agent model and a modular platform. Agents can perform multitask activities as well as move among different platforms. The MAS is hosted in a modular environment so that the platform can be customised. Several tools come with the programming suite, in particular: a visual protocol designer and a set of language extensions integrated into a professional development environment to ease development.