Abstract. Development of integrated programming environments has faced two problems: response degression, with an incresing execution delay when more tools have been included in an environment, and poor extensibility, with difficulties in adding new tools to an environment. Framework of a multitasking C+ + based programming environment MCPE has been presented here for solving these problems. MCPE contains several concurrent tasks (processes): one of them is interacting with the user and the others are simultaneously doing their jobs. Process scheduling and concurrency control in MCPE have been carefully designed: response time is then reduced, and unnecessary computations are avoided. An event-driven serving model providing flexible task communications eases the addition of tools. Shared data stores have been defined as monitor types with no nested monitor calls in preventing deadlock. Consistency among the tasks has also been assured. A prototype has also been presented to show feasibility.