Will Norris‘ talk at WordCamp PDX introduces WordPress coding standards, common functions, and constants to would be plugin developers (and smacks those who’ve already done it wrong). Also notable: functions, classes, variables, and constants in the WordPress trunk.
Just as WordPress has a number of hooks and filters that plugins can use to modify and extend behavior, it also has a cool way to customize the installation process.
Extending The WYSIWYG Editor
TinyMCE, the WYSIWYG editor in WordPress has a rich API to allow adding buttons and stuff, but the docs are hard to get into. We can get a jump on that by looking at how it’s implemented in other WP plugins. This code creates the buttons, while the function that responds to the button click and does the work is defined within the plugin. The TinyMCE plugins in core are also informative.