diff --git a/html/images/big.picture.png b/html/images/big.picture.png
new file mode 100644
index 00000000..10cf59fe
Binary files /dev/null and b/html/images/big.picture.png differ
diff --git a/html/used.components.html b/html/used.components.html
index 48abcbb9..74d47ae6 100644
--- a/html/used.components.html
+++ b/html/used.components.html
@@ -21,72 +21,72 @@
 <tbody>
 
 <tr>
-<th>Postfix</th>
+<td><a href="http://www.postfix.org" target="_blank">Postfix</a></td>
 <td>Mail Transfer Agent (MTA)</td>
 </tr>
 
 <tr>
-<th>Dovecot</th>
+<td><a href="http://www.dovecot.org" target="_blank">Dovecot</a></td>
 <td>POP3, IMAP and Managesieve server</td>
 </tr>
 
 <tr>
-<td>Apache, Nginx</td>
+<td><a href="http://httpd.apache.org" target="_blank">Apache</a>, <a href="http://nginx.org" target="_blank">Nginx</a></td>
 <td>Web server</td>
 </tr>
 
 <tr>
-<td>OpenLDAP</td>
-<td>LDAP server, an optional for storing mail accounts.</td>
+<td><a href="http://www.openldap.org" target="_blank">OpenLDAP</a>, <a href="http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man8/ldapd.8?query=ldapd&arch=i386" target="_blank">ldapd(8)</a></td>
+<td>LDAP server, used for storing mail accounts (optional).</td>
 </tr>
 
 <tr>
-<td>MySQL, MariaDB, PostgreSQL</td>
+<td><a href="http://www.mysql.com" target="_blank">MySQL</a>, <a href="https://mariadb.org" target="_blank">MariaDB</a>, <a href="http://www.postgresql.org" target="_blank">PostgreSQL</a></td>
 <td>SQL server used to store application data. Could be used to store mail accounts too.</td>
 </tr>
 
 <tr>
-<td>Amavisd</td>
+<td><a href="http://www.amavis.org" target="_blank">Amavisd-new</a></td>
 <td>Interface between Postfix and SpamAssassin, ClamAV. it calls SpamAssassin and ClamAV for content-based spam/virus scanning.</td>
 </tr>
 
 <tr>
-<td>SpamAssassin</td>
+<td><a href="http://spamassassin.apache.org" target="_blank">SpamAssassin</a></td>
 <td>content-based spam scanner</td>
 </tr>
 
 <tr>
-<td>ClamAV</td>
+<td><a href="http://www.clamav.net/index.html" target="_blank">ClamAV</a></td>
 <td>Virus scanner</td>
 </tr>
 
 <tr>
-<td>Cluebringer</td>
+<td><a href="http://www.policyd.org" target="_blank">Cluebringer</a></td>
 <td>A third-party postfix policy server</td>
 </tr>
 
 <tr>
-<td>iRedAPD</td>
+<td><a href="https://bitbucket.org/zhb/iredapd/" target="_blank">iRedAPD</a></td>
 <td>A very simple postfix policy server developed by iRedMail team</td>
 </tr>
 
 <tr>
-<td>Roundcube</td>
+<td><a href="http://roundcube.net" target="_blank">Roundcube</a></td>
 <td>Webmail (PHP)</td>
 </tr>
 
 <tr>
-<td>SOGo Groupware</td>
+<td><a href="http://sogo.nu" target="_blank">SOGo Groupware</a></td>
 <td>A groupware which provides calendar (CalDAV), contact (CardDAV) and ActiveSync services.</td>
 </tr>
 
 <tr>
-<td>Fail2ban</td>
+<td><a href="http://www.fail2ban.org" target="_blank">Fail2ban</a></td>
 <td>Scans log files and bans IPs that show the malicious signs -- too many password failures, seeking for exploits, etc.</td>
 </tr>
 
 <tr>
-<td>Awstats</td>
+<td><a href="http://www.awstats.org" target="_blank">Awstats</a></td>
 <td>Apache and Postfix log analyzer</td>
 <td></td>
 </tr>
@@ -94,6 +94,8 @@
 </tbody>
 </table>
 
+<h1 id="the-big-picture">The Big Picture</h1>
+<p><img alt="" src="./images/big.picture.png" /></p>
 <h1 id="see-also">See also</h1>
 <ul>
 <li><a href="./file.locations.html">Locations of configuration and log files of mojor components</a></li>
diff --git a/overview/0-used.components.md b/overview/0-used.components.md
index 45fa22a1..1ee063f6 100644
--- a/overview/0-used.components.md
+++ b/overview/0-used.components.md
@@ -10,72 +10,72 @@
 <tbody>
 
 <tr>
-<th>Postfix</th>
+<td><a href="http://www.postfix.org" target="_blank">Postfix</a></td>
 <td>Mail Transfer Agent (MTA)</td>
 </tr>
 
 <tr>
-<th>Dovecot</th>
+<td><a href="http://www.dovecot.org" target="_blank">Dovecot</a></td>
 <td>POP3, IMAP and Managesieve server</td>
 </tr>
 
 <tr>
-<td>Apache, Nginx</td>
+<td><a href="http://httpd.apache.org" target="_blank">Apache</a>, <a href="http://nginx.org" target="_blank">Nginx</a></td>
 <td>Web server</td>
 </tr>
 
 <tr>
-<td>OpenLDAP</td>
-<td>LDAP server, an optional for storing mail accounts.</td>
+<td><a href="http://www.openldap.org" target="_blank">OpenLDAP</a>, <a href="http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man8/ldapd.8?query=ldapd&arch=i386" target="_blank">ldapd(8)</a></td>
+<td>LDAP server, used for storing mail accounts (optional).</td>
 </tr>
 
 <tr>
-<td>MySQL, MariaDB, PostgreSQL</td>
+<td><a href="http://www.mysql.com" target="_blank">MySQL</a>, <a href="https://mariadb.org" target="_blank">MariaDB</a>, <a href="http://www.postgresql.org" target="_blank">PostgreSQL</a></td>
 <td>SQL server used to store application data. Could be used to store mail accounts too.</td>
 </tr>
 
 <tr>
-<td>Amavisd</td>
+<td><a href="http://www.amavis.org" target="_blank">Amavisd-new</a></td>
 <td>Interface between Postfix and SpamAssassin, ClamAV. it calls SpamAssassin and ClamAV for content-based spam/virus scanning.</td>
 </tr>
 
 <tr>
-<td>SpamAssassin</td>
+<td><a href="http://spamassassin.apache.org" target="_blank">SpamAssassin</a></td>
 <td>content-based spam scanner</td>
 </tr>
 
 <tr>
-<td>ClamAV</td>
+<td><a href="http://www.clamav.net/index.html" target="_blank">ClamAV</a></td>
 <td>Virus scanner</td>
 </tr>
 
 <tr>
-<td>Cluebringer</td>
+<td><a href="http://www.policyd.org" target="_blank">Cluebringer</a></td>
 <td>A third-party postfix policy server</td>
 </tr>
 
 <tr>
-<td>iRedAPD</td>
+<td><a href="https://bitbucket.org/zhb/iredapd/" target="_blank">iRedAPD</a></td>
 <td>A very simple postfix policy server developed by iRedMail team</td>
 </tr>
 
 <tr>
-<td>Roundcube</td>
+<td><a href="http://roundcube.net" target="_blank">Roundcube</a></td>
 <td>Webmail (PHP)</td>
 </tr>
 
 <tr>
-<td>SOGo Groupware</td>
+<td><a href="http://sogo.nu" target="_blank">SOGo Groupware</a></td>
 <td>A groupware which provides calendar (CalDAV), contact (CardDAV) and ActiveSync services.</td>
 </tr>
 
 <tr>
-<td>Fail2ban</td>
+<td><a href="http://www.fail2ban.org" target="_blank">Fail2ban</a></td>
 <td>Scans log files and bans IPs that show the malicious signs -- too many password failures, seeking for exploits, etc.</td>
 </tr>
 
 <tr>
-<td>Awstats</td>
+<td><a href="http://www.awstats.org" target="_blank">Awstats</a></td>
 <td>Apache and Postfix log analyzer</td>
 <td></td>
 </tr>
@@ -83,6 +83,10 @@
 </tbody>
 </table>
 
+# The Big Picture
+
+![](./images/big.picture.png)
+
 # See also
 
 * [Locations of configuration and log files of mojor components](./file.locations.html)