If you are new to WordPress, but already know how to program, the typical "Hello, World" examples aren't helpful. You need to know how to make the right API calls, and where to find documentation about the actions and filters that WordPress makes available to you.
This presentation is a brief introduction skimming the surface of the API hook system in WordPress. It does not go into deep detail, but gives brief "real world" examples of how to use filters and actions, along with pointers on where to find the main documentation that will help you get started on your own plugins.
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