An event-driven execution monitor named EDEN for Ada tasking programs is presented. EDEN reports tasking behavior of the monitored program and detects tasking communication deadlocks in the program at runtime. The authors use it as a testing and/or debugging tool in developing Ada tasking programs at the Ada source code level. They tried to make EDEN transparent for any monitored Ada program with respect to the partial order of tasking events of the program. The authors discuss their monitoring method and describe the design and implementation of EDEN.