Ext plugins are a powerful way to extend Liferay. There are no limits to what you can use them to customize, so use them carefully. Before using an Ext plugin, see if you can implement all or part of the desired functionality through a different plugin type: portlets, hooks, and web plugins offer you a lot of extension capabilities themselves, without introducing the complexity that’s inherent with Ext plugins. If you need to use an Ext plugin, make it as small as possible and follow the instructions in this guide carefully to avoid issues.
Next we’ll learn how to develop Liferay using the Maven build framework.