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+Overview
+========
+
+Pagure is split over multiple components, each having their interest and all
+but one (the core application) being optional.
+
+These components are:
+
+.. contents::
+
+
+Pagure core application
+-----------------------
+
+The core application is the flask application interacting with gitolite to
+provide a web UI to these git repositories as well as tickets and
+pull-requests.
+This is the main application for the forge.
+
+
+Pagure doc server
+-----------------
+
+While integrated into the main application at first, it has been split out
+for security concern, displaying information directly provided by the user
+without a clear/safe way of filtering for un-safe script or hacks is a
+security hole.
+For this reason we also strongly encourage anyone wanting to deploy their
+own instance of pagure with the doc server, to run this application on an
+completely different domain name (not just a sub-domain) in order to reduce
+the cross-site forgery risks.
+
+Pagure can be run just fine without the doc server, all you need to do is to
+**not** define the variable ``DOC_APP_URL`` in the configuration file.
+
+
+Pagure milter
+-------------
+
+The milter is a script, receiving an email as input and performing an action
+with it.
+
+In the case of pagure, the milter is used to allow replying on a comment
+of a ticket or a pull-request by directly replying to the notification sent.
+No need to go to the page anymore to reply to a comment someone made.
+
+The milter integrates with an smtp server such as postfix or sendmail that
+you will have running and have access to in order to change its configuration.
+
+
+Pagure EventSource Server
+-------------------------
+
+Eventsource or Server Sent Events are messages sent from a server to a browser.
+
+For pagure this technology is used to allow live-refreshing of a page when
+someone is viewing it. For example, while you are reading a ticket if someone
+comments on it, the comment will automatically show up on the page without
+the need for you to reload the entire page.