A gear is a portal component that’s been developed and deployed for the ATG Portal platform. Here are some of the principal differences between gears and portlets:
| Gears | Portlets | 
|---|---|
| Organized as a separate J2EE Web application | Similar, but not a Web application | 
| Can be completely written as JSPs | Must include one Java class, the Portlet class | 
| Can use  | May not use  | 
If you are designing a new portal component, you need to decide whether to develop it as a portlet or a gear. If you develop it as a gear, you may be able to take advantage of ServletFilters and other features that are not available to portlets. However, if you develop it as a portlet, your new component will be portable and able to run (after processing) on other portal platforms, as well on the ATG Portal.

