Continuing with the restructuring.

Making space for libraries.
Bringing security themed topics under single subject.

_includes/input-filtering.md

@@ -1,15 +0,0 @@
-# Input Filtering
-
-Never ever (ever) trust foreign input introduced to your PHP code. That leads to dark and dangerous places. Instead, always filter foreign input before you use it in your code.
-
-PHP provides the `filter_var` and `filter_input` functions to help you do this. These two functions can sanitize text, verify formats (e.g. email addresses), and escape characters.
-
-For example, if you accept code from an HTML form, you'll want to use `filter_input` before inserting the input into a database or inserting the input into an HTML response.
-
-* [Learn about `filter_var`][1]
-* [Learn about `filter_input`][2]
-
-[Back to Top](#top){.top}
-
-[1]: http://php.net/manual/en/function.filter-var.php
-[2]: http://www.php.net/manual/en/function.filter-input.php

_includes/libraries-and-frameworks.md

@@ -1,10 +1,12 @@
-# Popular Frameworks
+# Libraries and Frameworks
+
+## Web Frameworks
 
 Rather than re-invent the wheel, many PHP developers use _frameworks_ to build out web applications. Frameworks abstract away many of the low-level concerns and provide helpful, easy-to-use interfaces to complete common tasks.
 
 _You do not need to use a framework for every project_. Sometimes, plain PHP is the right way to go. But if you do need a framework, here are a few of the most popular ones (in alphabetical order):
 
-## Full-Stack Frameworks
+### Full-Stack Frameworks
 
 * [CakePHP](http://cakephp.org/)
 * [CodeIgniter](http://codeigniter.com/)
@@ -16,11 +18,10 @@ _You do not need to use a framework for every project_. Sometimes, plain PHP is
 * [Yii](http://www.yiiframework.com/)
 * [Zend](http://framework.zend.com/)
 
-## Micro Frameworks
+### Micro Frameworks
 
 * [Fat-Free](http://bcosca.github.com/fatfree/)
 * [Limonade](http://limonade-php.github.com/)
 * [Silex](http://silex.sensiolabs.org/)
 * [Slim](http://www.slimframework.com/)
 
-[Back to Top](#top){.top}

_includes/passwords.md

@@ -1,17 +0,0 @@
-# Password Hashing with Bcrypt
-
-Eventually everyone builds a PHP application that relies on user login. Usernames and (hashed) passwords are stored in a database and later used to authenticate users upon login.
-
-It is important that you properly _hash_ passwords that are stored in a database. If passwords are not hashed, and your database is hacked or accessed by an unauthorized third-party, all user accounts are now compromised.
-
-**Hash passwords with Bcrypt**. It's super simple, and (for all intents and purposes) Bcrypt makes it impossible for someone to reverse-engineer the plain-text version of a password should the database be compromised.
-
-There are several Bcrypt libraries for PHP that you may use.
-
-* [Read "How to Safely Store a Password" by Coda Hale][1]
-* [Use Bcrypt with PHPAss][2] (odd name, I know)
-
-[Back to Top](#top){.top}
-
-[1]: http://codahale.com/how-to-safely-store-a-password/
-[2]: http://www.openwall.com/phpass/

_includes/resources.md

@@ -1,6 +1,4 @@
-# Links and Resources
-
-Here are some miscellaneous resources that are worth a read.
+# Resources
 
 ## From the Source
 

_includes/security.md

@@ -0,0 +1,43 @@
+# Security
+
+## Web Application Security
+
+There are bad people ready and willing to exploit your web application. It is important that you
+ take necessary precautions to harden your web application's security. Luckily, the fine folks at [The Open Web Application Security Project][1] (OWASP) have compiled a comprehensive list of known security issues and methods to protect yourself against them. This is a must read for the security-conscious developer.
+
+* [Read the OWASP Security Guide][2]
+
+[1]: https://www.owasp.org/
+[2]: https://www.owasp.org/index.php/Guide_Table_of_Contents
+
+## Password Hashing with Bcrypt
+
+Eventually everyone builds a PHP application that relies on user login. Usernames and (hashed) passwords are stored in a database and later used to authenticate users upon login.
+
+It is important that you properly _hash_ passwords that are stored in a database. If passwords are not hashed, and your database is hacked or accessed by an unauthorized third-party, all user accounts are now compromised.
+
+**Hash passwords with Bcrypt**. It's super simple, and (for all intents and purposes) Bcrypt makes it impossible for someone to reverse-engineer the plain-text version of a password should the database be compromised.
+
+There are several Bcrypt libraries for PHP that you may use.
+
+* [Read "How to Safely Store a Password" by Coda Hale][3]
+* [Use Bcrypt with PHPAss][4] (odd name, I know)
+
+[3]: http://codahale.com/how-to-safely-store-a-password/
+[4]: http://www.openwall.com/phpass/
+
+## Input Filtering and Sanitizing
+
+Never ever (ever) trust foreign input introduced to your PHP code. That leads to dark and dangerous places. Instead, always filter foreign input before you use it in your code.
+
+PHP provides the `filter_var` and `filter_input` functions to help you do this. These two functions can sanitize text, verify formats (e.g. email addresses), and escape characters.
+
+For example, if you accept code from an HTML form, you'll want to use `filter_input` before inserting the input into a database or inserting the input into an HTML response.
+
+* [Learn about `filter_var`][5]
+* [Learn about `filter_input`][6]
+
+[5]: http://php.net/manual/en/function.filter-var.php
+[6]: http://www.php.net/manual/en/function.filter-input.php
+
+[Back to Top](#top){.top}

_includes/web-application-security.md

@@ -1,11 +0,0 @@
-# Web Application Security
-
-There are bad people ready and willing to exploit your web application. It is important that you
- take necessary precautions to harden your web application's security. Luckily, the fine folks at [The Open Web Application Security Project][1] (OWASP) have compiled a comprehensive list of known security issues and methods to protect yourself against them. This is a must read for the security-conscious developer.
-
-* [Read the OWASP Security Guide][2]
-
-[Back to Top](#top){.top}
-
-[1]: https://www.owasp.org/
-[2]: https://www.owasp.org/index.php/Guide_Table_of_Contents