You have seen how easy it is to write your own desktop applications using PHP-GTK in the article "Building Your Own Desktop Notepad Application Using PHP-GTK." Once you have learned how to write desktop applications using PHP-GTK, you will be pleased to know that writing system tray applications is just a matter of adding a couple of lines of code. The bulk of your code remains exactly the same!

They create a GtkStatusIcon widget (resulting in a generic file icon in the system tray) and show how to modify the previous Notepad application to respond to being clicked.