layers.txt
+----

Python web frameworks - layering

                                            (applications..)
                                                 ---------
                                                  Flask..  (applications..)
                              (echo_cgi,_wsgi)  ---------   ------------
                              (applications..)  Werkzeug..  Bottle .. Django ..
                            -----------------------------------------------
             (static pages..)   CGI         WSGI
 (echo_www)         -----------------------------------------------------------------
 (applic..) ws30 SimpleHTTPServer CGIHTTPServer wsgiref.simple_server Nginx Apache ..
 --------------------------------------------------------------------------
                                 socket

 ^  more layers       more, larger are not necessarily better
 |                      can build applications on any layer, at any scale 
 |                   
 +-----> larger, more complex