+ - <b>Migrating Actors</b>.
+ @ref examples/s4u/actor-migration/s4u-actor-migration.cpp @n
+ Actors can move or be moved from a host to another with the @ref
+ simgrid::s4u::this_actor::migrate() method.
+
+ - <b>Waiting for the termination of an actor</b> (joining on it)
+ @ref examples/s4u/actor-join/s4u-actor-join.cpp @n
+ The simgrid::s4u::Actor::join() method allows to block the current
+ actor until the end of the receiving actor.
+
+ - <b>Yielding to other actor</b>.
+ @ref examples/s4u/actor-yield/s4u-actor-yield.cpp@n
+ The simgrid::s4u::this_actor::yield() function interrupts the
+ execution of the current actor, leaving a chance to the other actors
+ that are ready to run at this timestamp.
+
+@subsection s4u_ex_actors_replay Traces Replay as a Workload
+
+This section details how to run trace-driven simulations. It is very
+handy when you want to test an algorithm or protocol that only react
+to external events. For example, many P2P protocols react to user
+requests, but do nothing if there is no such event.
+
+In such situations, you should write your protocol in C++, and separate
+the workload that you want to play onto your protocol in a separate
+text file. Declare a function handling each type of the events in your
+trace, register them using @ref xbt_replay_action_register in your
+main, and then run the simulation.
+
+Then, you can either have one trace file containing all your events,
+or a file per simulated process: the former may be easier to work
+with, but the second is more efficient on very large traces. Check
+also the tesh files in the example directories for details.
+
+ - <b>Communication replay</b>.
+ @ref examples/s4u/replay-comm/s4u-replay-comm.cpp @n
+ Presents a set of event handlers reproducing classical communication
+ primitives (asynchronous send/receive at the moment).
+
+ - <b>I/O replay</b>.
+ @ref examples/s4u/replay-storage/s4u-replay-storage.cpp @n
+ Presents a set of event handlers reproducing classical I/O
+ primitives (open, read, close).
+
+@section s4u_ex_activities Activities: the things that Actors do
+
+@subsection s4u_ex_activity_comm Communications on the network