-/** \addtogroup MSG_API
-
-MSG was the first distributed programming environment provided within SimGrid,
-and is still the most commonly used nowadays. If you are unsure of the interface
-you should use, they you probably want to use MSG. It constitutes a convenient
-simplification of the reality of distributed systems. It can be used to build
-rather realistic simulations, but remains simple to use: most unpleasant
-technical elements can be abstracted away rather easily. If you want to use the
-C programming language, your are in the right section. If you prefer not to use
-this venerable but demanding language, please refer to the @ref MSG_Java section.
-
-If you think that MSG may not be the interface you need, please consider the
-other user interfaces provided by SimGrid: If you want to use DAGs, have a look
-at the \ref SD_API programming environment. If you want to study an existing MPI
-program, have a look at the \ref SMPI_API one. If none of those programming
-environments fits your needs, you may consider implementing your own directly on
-top of \ref SIMIX_API, or even on top of \ref SURF_API (but you want to contact
-us before digging into these badly documented internal modules).
-
-
-
-\section MSG_funct Offered functionalities
- - \ref msg_simulation
- - \ref m_process_management
- - \ref m_host_management
- - \ref m_task_management
- - \ref msg_mailbox_management
- - \ref msg_file_management
- - \ref msg_task_usage
- - \ref msg_VMs
- - \ref msg_synchro
- - \ref msg_trace_driven
- - \ref MSG_examples
-
-
- Also make sure to visit the page @ref MSG_examples.
-*/
-
-
+/**
+@defgroup MSG_API MSG: Legacy handling of CSP algorithms
+@brief Simple programming environment
+
+
+MSG is a simple API to write algorithms organized with Concurrent
+Sequential Processes (CSP) that interact by exchanging messages. It
+constitutes a convenient simplification of the reality of distributed
+systems. It can be used to build rather realistic simulations, but
+remains simple to use: most unpleasant technical elements can be
+abstracted away rather easily.
+
+@warning MSG used to be the main API of SimGrid 3, but we are
+ currently in the process of releasing SimGrid 4. The
+ tentative release date is Summer 2018. So MSG is frozen and
+ will probably never evolve. If you are starting a new
+ project, you should consider S4U instead. Note that the
+ support for MSG will not be removed from SimGrid before 2020
+ at least.
+
+@section MSG_funct Offered functionalities
+ - @ref msg_simulation
+ - @ref m_process_management
+ - @ref m_host_management
+ - @ref m_task_management
+ - @ref msg_mailbox_management
+ - @ref msg_file
+ - @ref msg_task_usage
+ - @ref msg_VMs
+ - @ref msg_synchro
+ - @ref msg_examples
+
+*/