components.xml:

<transaction:ejb-transaction/>

EjbTransaction.java:

/**
 * Dummy component that lets us install the
 * EjbSynchronizations via the tag
 * transaction:ejb-transaction
 *
 * @see EjbSynchronizations
 * @author Gavin King
 * 
 */
@Name("org.jboss.seam.transaction.ejbTransaction")
@Scope(ScopeType.STATELESS)
@Install(precedence=BUILT_IN, value=false)
@BypassInterceptors
public class EjbTransaction {}

EjbSynchronizations.java:

/**
 * Receives JTA transaction completion notifications from 
 * the EJB container, and passes them on to the registered
 * Synchronizations. This implementation
 * is fully aware of container managed transactions and is 
 * able to register Synchronizations for the container 
 * transaction.
 * 
 * @author Gavin King
 *
 */
@Stateful
@Name("org.jboss.seam.transaction.synchronizations")
@Scope(ScopeType.EVENT)
@Install(precedence=FRAMEWORK, dependencies="org.jboss.seam.transaction.ejbTransaction")
@BypassInterceptors
@TransactionAttribute(TransactionAttributeType.SUPPORTS)
public class EjbSynchronizations implements LocalEjbSynchronizations, SessionSynchronization{...}

Somebody plz explain how this exactly works in terms of install/init, etc. and exactly what the purpose of EjbSynchronizations is (also what if you're using BMT?).

Both have @Install annotations, one is higher precedence that the other (BUILT_IN = 0, FRAMEWORK = 10).

So when Seam reads <transaction:ejb-transaction/> in components.xml what happens?

I'm assuming that the init routine which scans for all Seam components looking for @Name runs during deployment of EAR/WAR first and then the components.xml contents are parsed.  Is this correct?