Grammatical improvements to some of the documentation.

Signed-off-by: Bill Allen <photo.allen@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

README.rst

@@ -2,7 +2,7 @@ What's Ryu
 ==========
 Ryu is a component-based software defined networking framework.
 
-Ryu provides software components with well defined API that make it
+Ryu provides software components with well defined API's that make it
 easy for developers to create new network management and control
 applications. Ryu supports various protocols for managing network
 devices, such as OpenFlow, Netconf, OF-config, etc. About OpenFlow,
@@ -33,14 +33,14 @@ After writing your application, just type::
 Optional Requirements
 =====================
 
-Some functionalities of ryu requires extra packages:
+Some functions of ryu require extra packages:
 
 - OF-Config requires lxml and ncclient
 - NETCONF requires paramiko
 - BGP speaker (SSH console) requires paramiko
 - Zebra protocol service (database) requires SQLAlchemy
 
-If you want to use the functionalities, please install requirements::
+If you want to use these functions, please install the requirements::
 
     % pip install -r tools/optional-requires
 
@@ -49,8 +49,8 @@ Please refer to tools/optional-requires for details.
 
 Prerequisites
 =============
-If you got some error messages at installation step, please confirm
-dependencies for building required Python packages.
+If you got some error messages at the installation stage, please confirm
+dependencies for building the required Python packages.
 
 On Ubuntu(16.04 LTS or later)::
 

doc/source/writing_ryu_app.rst

@@ -5,21 +5,21 @@ The First Application
 Whetting Your Appetite
 ======================
 
-If you want to manage the network gears (switches, routers, etc) at
-your way, you need to write your Ryu application. Your application
-tells Ryu how you want to manage the gears. Then Ryu configures the
-gears by using OpenFlow protocol, etc.
+If you want to manage network gear (switches, routers, etc) your
+own way, you just need to write your own Ryu application. Your application
+tells Ryu how you want to manage the gear. Then Ryu configures the
+gear by using OpenFlow protocol, etc.
 
-Writing Ryu application is easy. It's just Python scripts.
+Writing Ryu applications is easy. They're just Python scripts.
 
 
 Start Writing
 =============
 
-We show a Ryu application that make OpenFlow switches work as a dumb
+Here we show a Ryu application that makes an OpenFlow switch work as a dumb
 layer 2 switch.
 
-Open a text editor creating a new file with the following content:
+Open a text editor and create a new file with the following content:
 
 .. code-block:: python
    
@@ -29,9 +29,9 @@ Open a text editor creating a new file with the following content:
        def __init__(self, *args, **kwargs):
            super(L2Switch, self).__init__(*args, **kwargs)
 
-Ryu application is just a Python script so you can save the file with
-any name, extensions, and any place you want. Let's name the file
-'l2.py' at your home directory.
+Ryu applications are just Python scripts so you can save the file with
+any name, any extension, and any place you want. Let's name the file
+'l2.py' in your home directory.
 
 This application does nothing useful yet, however it's a complete Ryu
 application. In fact, you can run this Ryu application::
@@ -41,10 +41,10 @@ application. In fact, you can run this Ryu application::
    instantiating app /Users/fujita/l2.py
 
 
-All you have to do is defining needs a new subclass of RyuApp to run
+All you have to do is define a new subclass of RyuApp to run
 your Python script as a Ryu application.
 
-Next let's add the functionality of sending a received packet to all
+Next let's add some functionality that sends a received packet to all
 the ports.
 
 .. code-block:: python
@@ -75,18 +75,18 @@ the ports.
            dp.send_msg(out)
 
 
-A new method 'packet_in_handler' is added to L2Switch class. This is
-called when Ryu receives an OpenFlow packet_in message. The trick is
+A new method 'packet_in_handler' is added to the L2Switch class. This is
+called when Ryu receives an OpenFlow packet_in message. The trick is the
 'set_ev_cls' decorator. This decorator tells Ryu when the decorated
 function should be called.
 
-The first argument of the decorator indicates an event that makes
-function called. As you expect easily, every time Ryu gets a
+The first argument of the decorator indicates which type of event this
+function should be called for. As you might expect, every time Ryu gets a
 packet_in message, this function is called.
 
-The second argument indicates the state of the switch. Probably, you
+The second argument indicates the state of the switch. You probably
 want to ignore packet_in messages before the negotiation between Ryu
-and the switch finishes. Using 'MAIN_DISPATCHER' as the second
+and the switch is finished. Using 'MAIN_DISPATCHER' as the second
 argument means this function is called only after the negotiation
 completes.
 
@@ -103,20 +103,20 @@ Ready for the second half.
 
 * OFPActionOutput class is used with a packet_out message to specify a
   switch port that you want to send the packet out of. This
-  application need a switch to send out of all the ports so OFPP_FLOOD
-  constant is used.
+  application uses the OFPP_FLOOD flag to indicate that the packet should
+  be sent out on all ports.
 
 * OFPPacketOut class is used to build a packet_out message.
 
 * If you call Datapath class's send_msg method with a OpenFlow message
-  class object, Ryu builds and send the on-wire data format to the switch.
+  class object, Ryu builds and sends the on-wire data format to the switch.
 
 
-Here, you finished implementing your first Ryu application. You are ready to
-run this Ryu application that does something useful.
+There, you finished implementing your first Ryu application. You are ready to
+run a Ryu application that does something useful.
 
 
-A dumb l2 switch is too dumb? You want to implement a learning l2
+Is a dumb L2 switch is too dumb? You want to implement a learning L2
 switch? Move to `the next step
 <https://github.com/osrg/ryu/blob/master/ryu/app/simple_switch.py>`_. You
 can learn from the existing Ryu applications at `ryu/app