# JMap Server Extensions

JMap standard features can be extended to provide new specialized functions. This is done using JMap extensions. 

A JMap extension is an optional module that can be plugged into JMap Server and/or JMap applications in order to provide the desired set of new functions. 

The extensions installed in your JMap Server are displayed in the [Installed Extensions](https://docs-jmapserver-lima.k2geospatial.com/e/administrator/jmap-server-administrator-manual/jmap-server-extensions/installed-extensions) section.

 The available extensions are presented in the [Marketplace](https://docs-jmapserver-lima.k2geospatial.com/e/administrator/jmap-server-administrator-manual/jmap-server-extensions/marketplace) of the **Extensions** section.

Organizations can also develop their own extensions using the [JMap Server SDK](https://docs-jmapserver-lima.k2geospatial.com/v/jmapserversdk).