Extrait de la documentation liferay :

"Liferay Portal, since it adheres to the JSR standard for portlets, was designed from the ground up for application integration. You can add any application installed on the system to any page in the portal. You can make use of APIs provided by other systems to integrate their data into an application window in Liferay. And applications you create with Liferay’s Service Builder API are web service-enabled from the start."

 

Article Wikipedia sur JSR