Liferay
What is Liferay
Liferay is an upcoming and very famous open source solution for building portal based applications. If you are not familiar with what a portal then please visit iGoogle to see how a portal looks like. A portal is something which acts as container for various other smaller applications running as portlets within the portal container.
Features provided by Liferay
Coming to more details, it offers various features to the application developer in order to meet the functionality of the client in an easier way. For example, there is out of the box support for Chat, Message Boards, Calendar,Blog,Wiki, Document Management in Liferay. These features only a subset of all the features provided by Liferay.
In addition to these out of the box features provided by this tool, these features can be customized to the extreme extent because of the open source nature of Liferay. The customization is made easy by providing hooks. Also, one can completely customize the look and feel of this portal.
This tool doesn’t use EJB or JMS, it can be deployed an a servlet engine like Tomcat. The best part is that Liferay uses the latest technologies and tools to build the features. Some of the Java technologies used by this tool include jQuery, VAADIN, Spring, Hibernate, Solr, Velocity, FreeMarker etc. This ensures best technologies are available to one when using Liferay.
Liferay also has a tool named Service Builder which helps in generating the helper code for interacting with databases. The databases supported by Liferay include HSQL,MySQL,MS SQL Server,Oracle,DB2 etc.
There are two versions of Liferay available. One is community edition which is free and the other is enterprise edition which has paid support. Since this portal has strong user base, getting around the popular blockers is not that difficult. Enterprise edition should be used when professional consulting is required.
Thus if one wants, it can be used without spending anything on purchasing licenses.
Liferay Tutorials
Database Interaction Liferay
50 Liferay Interview Questions
Liferay Portals and Portlets Books List
Generating Liferay Database Tables