Of course, it does. Live sites: www.sesamestreet.org - using Spring MVC portlets.
Portlets in Plugins SDK can make use of any application framework that Liferay supports, for example,
JSF, JSP, Rubby, Lazzlo, PHP, JSON, Hibernate, DAO, Spring MVC, Struts, Tapestry,
Wicket, Python, LAR (Liferay Archive), and so on. Therefore, if the work has nothing
related to extension and customization of the out of the box portlets, you should use
Plugins SDK environment. (Abstracted from Chapter 3)