JSR 286 vs JSR 168

Features	JSR 168 Specification	JSR 286 Specification
Inter Portlet Communication	·  Only supported within the same portlet application using session attributes · Target portlets will only "see" messages during next render request.	Add additional coordination capabilities · Limited only to String Values. · Sharing of session data beyond the current Portlet application. · Sharing of render parameters across portlets.
Life cycle	Portlets cannot update their state during a render request: "event" handling not really possible	New 3rd life cycle phase before rendering
Portlet Filters	Doesn't Support	· Supports Allow on the fly transformations of information in both the request to and the response from the portlet ·  Defined in portlet.xml
Caching		· Extended Cache support. ·Allow public cached content for multiple users
Common Web Frameworks	· Servlet dispatching not supported from process Action. · Needs Portals Bridges or similar solutions. · JSTL support very limited	·  Extended Cache support. · Allow public cached content for multiple users. · Improved support for web frameworks (Struts, JSF, Spring) Allow servlet dispatching during all lifecycle calls: processAction, processEvent, render, serverResource. · Extended JSP tag library <defineObjects/>, support for JSF
Non HTML Resources(pdf, doc, images etc.)	·  A portlet can only render html fragments. · Have to fallback/delegate to the servlet container. · Requires coordination between portlet and servlet.