--- /dev/null
+What's EFICAS
+==============
+
+Name's origin
+-------------
+EFICAS is the acronym of ' Editeur de FIchier de Commandes et Analyseur Sémantique'.
+That means that EFICAS allows users to write a parameter file for a code.
+It handles whith syntax and semantics.
+It avoids misuse of commands which are not allowed in a given context.
+It insures integrity of the file.
+
+General Behaviour
+------------------
+* Catalogs
+
+EFICAS can be used by multiple codes and handles with multiple versions of each code. It is customized with files named "Catalogue" : It contains all commands for a code. Each command has a name and parametres which are defined by developpers.
+
+
+* Outputs
+
+Eficas's output is a commands file named ".comm". It may be able to produce various file formats such as .xml for OpenTurns. However, you always must have a '.comm" output: this is the only format Eficas is able to reread.
+
+Both Command Files and Catalogs are python file. So you have to remind some
+:ref:`python-label`
+
+
