Cal Evans over the Zend Developer Zone says, WordPress attracted a lot of flak for it’s code and it’s history of security issues. But still he thinks it’s a flexible system and there is an ecosystem that has built up around it’s plugin-system. He mentions Bruno Goncalves who has boiled down the steps necessary to build a rudimentary plugin into an easy to understand tutorial.

Cal says the most difficult part about the entire process of plugins is to get started. Bruno's tutorial shows you how to write a simple plugin without much trouble.

Cal comments, the tutorial are only for the motivated. He says, Bruno glosses over some important issues to keep things simple. He does however, provide lots of source code to read and even a line to download the finished plugin so you can dissect the finished product. If you want to break into writing WordPress plugins, this is a good place to start, he adds.