Export Apple ICNS icon file from Adobe Illustrator
When you develop an application for Mac OS X you need to supply an application icon in the Apple properitary ICNS icon format (see here).
As it turns out the format is pretty simple. The different images are just concatenated. In between there have to be some header bytes and length information. Mac OS X 10.5 and above supports PNG images (which is the only inner format my script exports). To automate the task of exporting an icon in different resolutions and then packing them into an ICNS file I wrote a small export script.
You can find it at GitHub. Please feel free to contribute enhancements. The script is still very simple and might profit from some structural refactoring.