DefaultComponentManager or ExcaliburComponentManager ?

[cecile . mathis]

Hi,

I only want to know the difference between using DefaultServiceManager 
(ex-DefaultComponentManager)
from Avalon Framework and using ExcaliburComponentManager from Avalon 
Excalibur ? 

When shall I use  DefaultServiceManager and when is 
ExcaliburComponentManager better ?

Is there any documentation about it ?

Thanks,

Cecile