You also can use Medusa (http://www.nightmare.com/medusa/index.html) which implements the Half-Sync/Half-Async design pattern (http://www.cs.wustl.edu/~schmidt/patterns-ace.html) that is used in ACE (http://www.cs.wustl.edu/~schmidt/ACE.html) and TAO (http://www.cs.wustl.edu/~schmidt/TAO.html) -- Jody Winston