--- a/docs/index.rst	Wed Aug 30 11:25:27 2017 +0200
+++ b/docs/index.rst	Wed Aug 30 11:25:51 2017 +0200
@@ -119,6 +119,21 @@
     these editions. This is similar to Mercurial tracking the history of a file
     edition, but at the changeset level.
 
+Why the `evolve` extension
+--------------------------
+
+Mercurial core already has some support for changeset evolution so why have a
+dedicated extension?
+
+The long-term plan for ``evolve`` is to add it to core Mercurial. However,
+having the extension helps us experimenting with various user experience
+approaches and technical prototype. Having a dedicated extensions help current
+user to deploy the later changes quickly and provides the developers with
+low latency feedbacks.
+
+Whenever we are happy with a direction experimented in the extension, the
+relevant code go upstream.
+
 ``evolve`` is experimental!
 ---------------------------