Netbeans-plugin is a project mainly written in ..., it's free.
Nette Framework Support in NetBeans IDE
Because of plugin certification you must make your own build without the certificate. To allow that remove lines 'keystore=nbproject/private/keystore' and 'nbm_alias=myself' from the 'nbproject/project.properties' file.
download NetBeans IDE with JavaSE module
clone git repository - http://github.com/nette/netbeans-plugin
run NetBeans IDE and open cloned repository as a project
right click on the project name in the 'Project window'
left click on 'Create NBM'
when building is complete a '*.nbm' file is generated in the './build' directory
done :-)