Coming from Android/WP7 and having been involved in Symbian projects by the past, i would like now to exactly understand the Symbian App life cycle. I want to understand how the Apps are killed..

I found this:

"The Symbian platform is a modern preemptive multitasking operating system. Applications are created in their own process, running in a single main thread. The kernel preemptively schedules all threads in the system, based on their priority. While it is possible to create secondary threads, Symbian strongly encourages applications to co-operatively multi-task using active objects. ".
"(..) applications may be up and running at the same time and the user may switch between active applications. When a asynchronous event occurred, running application is moved to the background but it remains active".
My question is: How the system deals with the RAM issue? Is there any callback to indicate that the mobile is in low memory conditions? Any callback to indicate the App is about to be destroyed?
Does it mean that Symbian allows starting each single App, till there is not enough memory?
In UIQ framework i remember some kind of lowMemory() call-back, but one never used that..

Thanks, for your help..