Description: Struts is a framework for developing Web applications based on MVC design pattern under JEE platform (previously known as J2EE).

Description: Lucene is a text search engine used in information recovery. It is a technology suitable for nearly any application that requires indexing and full-text search. Lucene has been really useful in search engines development. PDF texts, HTML pages, Microsoft Word documents, and many others can be indexed while you get information from them.

Description: Hibernate is a relational-object mapping tool for Java, which makes mapping between a traditional relational database and an object oriented application much more easier, through declarative files which allow to create those links. Besides, it's open source software, under GNU LGPL license.