The need for rapid and cost-effective development Intelligent Tutoring Systems with flexible pedagogical approaches has led to a demand for authoring tools. The authoring systems developed to date provide a range of options and flexibility, such as authoring simulations, or authoring tutoring strategies. This paper describes FlexiTrainer, an authoring framework that enables the rapid creation of pedagogically rich and performance-oriented learning environments with custom content and tutoring strategies. FlexiTrainer provides tools for specifying the domain knowledge and derives its power from a visual behavior editor for specifying the dynamic behavior of tutoring agents that interact to deliver instruction. The FlexiTrainer runtime engine is an agent based system where different instructional agents carry out teaching related actions to achieve instructional goals. FlexiTrainer has been used to develop an ITS for training helicopter pilots in flying skills.