Event oriented systems are becoming present on many domains of applications. Distributed systems and graphical interactive systems are classical examples of environments that adapt well to the concept of event oriented programming. There are also emerging scenarios like cellphone runtime environments. Despite the growing presence on the computational systems, some challenges still remain, like efficient method dispatch models and the management of concurrent processing of the event handlers. This work propose a model for an event scheduler using collaborative routines. We introduce a study on some mainstream scheduler models and propose a model where the scheduler holds the responsibility to encapsulate the complexity of managing multiple lines of execution, minimizing the CPU time wasted with blocking methods. The coroutine model allows the management of these multiple lines of execution using a general control abstraction, which allows seamless context switching during the multiple suspending and resuming of the routine. Also, without preemption, there is no overhead due to access control of the shared resources. The proposed is tested on two different scenarios: one programming framework designed to be run mobile phones, a fully asynchronous environment with low processing power and severe memory constraints; and a CORBA middleware written in lua, where the communication between distributed objects is based on the remote procedure call modell.