Liferay 6.1 CE released

Introduction to Liferay

Liferay is a portal server. This means that it is designed to be a single environment where all of the applications a user needs can run, and these are integrated together in a consistent and systematic way. If an application lives outside the portal, the portal should be able to consume some resource of the application (such as an RSS feed or a subset of functionality in a "dashboard" application) so that the end user can see everything he or she interacts with at a glance.
To achieve this, all the application functionality within Liferay Portal resides in fragments of the page called portlets. Portlets are web applications that run in a portion of a web page. Liferay's core is a portlet container that aggregates portlets on particular pages and displays them to users. In this way, one or many applications can reside on a page, and users can (at the administrator's discretion) arrange them however they like.
Portlet applications, like servlet applications, are defined by a Java standard which various portal server vendors have implemented. The Java standard defines the portlet specification. A JSR-168 or JSR-286 standard portlet should be deployable on any portlet container which supports those standards. Portlets are placed on the page in a certain order by the end user and are served up dynamically by the portal server.
Portal applications generally come in two flavors: 1) multiple portlets which only provide small amounts of functionality individually, but are aggregated by the portal server into a larger application, or 2) whole applications which reside in only one application window. The choice is up to the application designers. Only developers have to worry about what happens inside the portlet itself. The portal server handles building out the page as it is presented to users.
Portlets are not difficult to build, and Java standard portlets can be written by any Java developer with experience in writing web applications. Liferay provides a Plugins Software Development Kit that makes it easy to design new portlet projects, as well as a development environment based on Eclipse. For further information about the Plugins SDK, please see Liferay Developer's Guide, which is the companion volume to this one, or Liferay in Action, published by Manning Publications, which is the official guide to Liferay development. For further information on Liferay's developer tools, see http://www.liferay.com/downloads/liferay-projects/liferay-ide.
Additionally, Liferay supports portlets written in other programming languages, such as PHP, Ruby, Groovy, or Python. Sample portlets written in these languages are available from Liferay's public plugin repository on Github at https://github.com/liferay/liferay-plugins.
We discuss the following topics in this chapter:

• Liferay's User Interface: How to navigate around Liferay
  
• Navigating the Control Panel: An overview of Liferay's control panel
  
• Portal Architechture: How Liferay organizes your portal
  

Navigation within Liferay Portal is designed to be intuitive and easy. Let's get started.

1. Navigating Liferay
2. Navigating the Control Panel
3. Portal Architecture
4. Summary

Refer here for details :-liferay 6.1 CE GA