<br/>
Describing your Simulated Platform
-==================================
+##################################
+
+In SimGrid, platforms are usually described in XML. This formalism has
+some drawbacks, but using a specific format ensures that the platform
+is not mixed with the tested application. This separation of concern
+:ref:`is a must <howto_science>` for your Modeling and Simulation (M&S)
+work. When XML is too limiting, you may describe your platforms using
+the :ref:`lua bindings <platform_lua>` (it is not yet possible to do so in
+python or directly in C++).
+
+We understand that writing a complex platform description can be tricky, we thus included
+:ref:`many examples <platform_examples>` in the archive. This
+documentation also contains some :ref:`hints and howtos <howto>`, as well
+as the full :ref:`XML reference guide <platform_reference>`.
+
+
+Any simulated platform must contain **basic elements**, such as hosts, links, storages, etc. SimGrid gives you a great
+liberty when defining the **routing of your platform**, i.e., the network path taken between each pair of hosts.
+Finally, you may also describe an **experimental scenario**, with qualitative (e.g., bandwidth variations representing
+an external load) and qualitative (e.g., representing how some elements fail and restart over time) changes.
+
+
+Defining Basic Elements
+***********************
+
+These are the components of your platform.
+
+
+There is not much to say about the definition of basic elements. Just
+use the appropriate tags: :ref:`pf_tag_host`, :ref:`pf_tag_link` and
+:ref:`pf_tag_storage`.
+
+Defining a Routing
+******************
+
+Performance Profiles and Churn
+******************************
+
+.. LocalWords: SimGrid
