Standards and freedesktop.org
Many of the integration tasks in this guide rely on standards which are relevant to more than GNOME. Other desktop projects like the K Desktop Environment also use these standards: if you integrate your applications with GNOME, you should have to do little or no extra work to make them run in those other environments as well.
Creating a perfect application is a wonderful feeling. Whether large or small, you want the desktop to recognize your application and for them to interact appropriately. With multiple desktops currently available, it is best for your application to be able to integrate itself in as many of them as possible. Even though no official rules have been adopted, there is a set of specifications available at freedesktop.org.
Although not a formal standards body, freedesktop.org maintains a set of informal but commonly agreed upon guidelines. When followed, these guidelines allow applications to be integrated on to compliant desktops.