Safari Extensions

A helpful tip for would-be extension developers:

“Compiled” Safari extensions are just renamed .zip files containing the HTML, CSS, Javascript, and other files that may make up an extension. If you’re curious how a certain extension does something, crack it open and have a good look!

EDIT: If OS X turns the .zip files into .zip.cpgz files instead of unzipping them, try using The Unarchiver or Rucksack instead.

EDIT 2: Marco Wessel (developer of Full-screen YouTube) notes that these are actually xar files. While my recommendation regarding The Unarchiver and Rucksack will work, you can also extract extensions on the command line by running:

xar -f ExampleExtension.safariextz -x