txt[
In most cases, you can extend Glyph just by creating your own =>[#macro_def|custom macros]. In some cases though, you may want to further customize Glyph to fit the needs of your project, in terms of creating =>[#custom_command|custom commands] and =>[#custom_task|custom tasks].

Glyph's modular architecture (and the Ruby language itself) lets you to add _arbitrary_ functionality to its core, simply by creating a few Ruby files and putting them in the right places.
]
section[
	@title[How Commands and Tasks work]
	@id[cmd_tasks_arch]
	txt[
Before creating custom Glyph commands and tasks, you should have a basic understanding on how they work, and which commands -- or better, which tasks -- are already available.

The following diagram outlines the relationships between commands and tasks:
	]
	figure[glyph/commands_tasks.png|Glyph default commands and tasks]
	txt[
As you can see:
* All commands call at at least one task.
* There are several task inter-dependencies spanning across three main Rake namespaces:
** @project:@ -- used for tasks affecting only the physical structure of the Glyph project.
** @load:@ -- used to load all kinds of files.
** @generate:@ -- used to generate files or copy files from source to output directories 
	]
	box[Example|
		txt[
Suppose you want to generate a PDF file by issuing the @glyph compile -f pdf@ command. Under the hood, Glyph calls the following tasks:
# @load:config@ -- Load the configuration files
# @load:tasks@  -- Load custom tasks (if any)
# @load:commands@ -- Load custom commands (if any)
# @load:snippets@ -- Load snippets from the @snippet.yml@ file
# @load:macros@ -- Load macros
# @load:all@ -- Dummy task used to call the previous ones
# @generate:document@ -- Parse, analyze and finalize the Glyph document
# @generate:images@ -- Copy images to the output directory (if any)
# @generate:styles@ -- Copy stylesheets to the output directory (if necessary)
# @generate:html@ -- Generate a standalone HTML file
# @generate:pdf@ -- Generate a PDF file from a standalone HTML file
		]
	]
]