Installation

Every plugin should be placed to the IDEA_HOME\plugins folder. It may be in jar or just a folder.

Plugin is in jar:

IDEA_HOME
	Plugins
		Sample.jar/
			com.intellij.....
				...
				...
			META-INF
				plugin.xml

Plugin is a folder:

IDEA_HOME
	Plugins
		Sample
			lib
			classes			
				com.intellij.....
				...
				...
			META-INF
				plugin.xml

Classes and lib folders are automatically added to the classpath.

Plugin configuration (plugin.xml)

<idea-plugin>
<!-- plugin name -->
  <name>Sample</name>
<!-- description -->
  <description>SamplePlugin</description>
<!-- plugin versuin -->
  <version>1.0</version>
  <vendor>IntelliJ</vendor>
<!-- minimum and maximum IDEA version plugin is supposed to work with -->
  <idea-version min="3.0" max="3.1"/>
<!-- application components of the plugin -->
  <application-components>
    <component>
<!-- component implementation class -->
      <implementation-class>com.intellij.openapi.samples.SampleApplicationPlugin</implementation-class>
<!-- component interface class -->
      <interface-class>com.intellij.openapi.samples.SampleApplicationPlugin</interface-class>
    </component>
  </application-components>
<!-- project components of the plugin -->
  <project-components>
    <component>
      <implementation-class>com.intellij.openapi.samples.SampleProjectPlugin</implementation-class>
      <interface-class>com.intellij.openapi.samples.SampleProjectPlugin</interface-class>
    </component>
  </project-components>
</idea-plugin>