Update readme

README.md

@@ -11,28 +11,47 @@ Installation
 
     gem install coffee-script
 
-*This compiler lib has replaced the original CoffeeScript compiler that was written in Ruby*
+*Note: This compiler library has replaced the original CoffeeScript
+ compiler that was written in Ruby.*
 
 
 Dependencies
 ------------
 
-The compiler depends on the `coffee-script-source` gem which is updated any time a new version of CoffeeScript is released. The gem's version number is sync'd up with the javascript release. This way you can build against different versions of CoffeeScript from this compiler.
+This library depends on the `coffee-script-source` gem which is
+updated any time a new version of CoffeeScript is released. (The
+`coffee-script-source` gem's version number is synced with each
+official CoffeeScript release.) This way you can build against
+different versions of CoffeeScript by requiring the correct version of
+the `coffee-script-source` gem.
 
-You can also use this lib with unreleased versions of CoffeeScript:
+In addition, you can use this library with unreleased versions of
+CoffeeScript by setting the `COFFEESCRIPT_SOURCE_PATH` environment
+variable:
 
     export COFFEESCRIPT_SOURCE_PATH=/path/to/coffee-script/extras/coffee-script.js
 
-The json library is also required but is not explicity stated as a gem dependency. If you're on 1.8 you'll need to install the json or json_pure gem. Its already included in 1.9.
+The `json` library is also required but is not explicitly stated as a
+gem dependency. If you're on Ruby 1.8 you'll need to install the
+`json` or `json_pure` gem. On Ruby 1.9, `json` is included in the
+standard library.
 
 
 Engines
 -------
 
-The `coffee-script` lib will automatically choose the best JavaScript engine for your platform. The currently implemented engines are:
+The `coffee-script` library will automatically choose the best
+JavaScript engine for your platform. The currently implemented engines
+are:
 
-* **Node.js**. If the `node` binary is available in $PATH, it will be used to invoke the CoffeeScript compiler.
+* **Node.js**. If the `node` binary is available in `$PATH`, it will
+    be used to invoke the CoffeeScript compiler.
 
-* **JavaScript Core**. If you're on OS X and don't have Node.js installed, the lib will fall back to the built-in JavaScript Core binary, `jsc`. This way you don't need any additional dependencies.
+* **JavaScript Core**. If you're on OS X and don't have Node.js
+    installed, the library will fall back to the built-in JavaScript
+    Core binary, `jsc`. This way you don't need to install any
+    additional dependencies.
 
-* **V8**. Shelling out to Node.js may be too slow for your production environment. In this case, install `therubyracer` gem, which provides a fast bridge between Ruby and V8.
+* **V8**. Shelling out to Node.js may be too slow for your production
+    environment. In this case, install `therubyracer` gem, which
+    provides a fast bridge between Ruby and V8.