-We have decided to change the units in SimGrid. Now we use Bytes, Flops and
-seconds instead of MBytes, MFlops and seconds... Units should be updated
-accordingly and the version of platform_description should be set to a
-valuer greater than 1:
+The format of the XML platform description files is sometimes
+improved. For example, we decided to change the units used in SimGrid
+from MBytes, MFlops and seconds to Bytes, Flops and seconds to ease
+people exchanging small messages. We also reworked the route
+descriptions to allow more compact descriptions.
+
+That is why the XML files are versionned using the 'version' attribute
+of the root tag. Currently, it should read: