Apache Cocoon is a Web development framework built around the concepts of separation of concerns and component-based Web development. Cocoon implements these concepts around the notion of "component pipelines", each component on the pipeline specializing on a particular operation. This makes it possible to use a Lego(tm)-like approach in building Web solutions, hooking together components into pipelines without any required programming.
The Apache JMeter is a 100% pure Java desktop application designed for performance and load testing of servers. It was primarily designed for Web/HTTP testing but it has been expanded to include support for a variety of testing modules. It ships with modules for HTTP and SQL databases (using JDBC). It may be used to test server performance both on static and dynamic resources, to simulate a heavy load on a server or network to test its strength, or to analyse overall performance under different load types. It also provides pluggable interfaces for customizing data visualization, test synchronization, and the construction and execution of tests.
Apache Jakarta Regexp is a 100% pure Java regular expression package. Expression syntax supports all of Perl5 syntax, with the exception of back reference substitution markers (several people have mentioned this lack, so please feel free to contribute a solution). It also supports a very limited subset of POSIX features. Performance and features are somewhat inferior to ORO, and the new JDK 1.4 (java.util.regex) package, but the package is especially small and features the ability to precompile expressions (without using object serialization) into byte arrays, thus avoiding the need to load the expression compiler.
The Turbine Development Kit (TDK) is a package that bundles a copy of Turbine, Tomcat, jar files, documentation, and other utilities in order to help you get started with Turbine as quickly as possible. Everything is pre-configured and ready to go. To get started, simply follow the instructions in the TDK download.
When building server side applications for the Web, independently of the language used (Java, PHP, Perl, etc), a lot of time is spent writing embedded HTML code and dealing with the fact that HTTP is a stateless protocol. SPFC allows you to write HTML forms like you write a Java GUI.
The goal of the Apache Tomcat Project is to provide commercial-quality server solutions based on the Java Platform that are developed in an open and cooperative fashion. Tomcat 3.x is an implementation of the Java Servlet 2.2 and JavaServer Pages 1.1 Specifications. Tomcat 4.x is an implementation of the Java Servlet 2.3 and JavaServer Pages 1.2 Specifications, and is a re-implementation of the Tomcat servlet engine from the ground up. The current branch, Tomcat 5.x, is an implementation of the Java Servlet 2.4 and JavaServer Pages 2.0 specifications, with increased attention to scalability, reliability, and management functionality.
Velocity is a Java-based template engine. It permits anyone to use the simple yet powerful template language to reference objects defined in Java code. When Velocity is used for Web development, Web designers can work in parallel with Java programmers to develop Web sites according to the Model-View-Controller (MVC) model, meaning that Web page designers can focus solely on creating a site that looks good, and programmers can focus solely on writing top-notch code. Velocity separates Java code from the Web pages, making the web site more maintainable over the long run and providing a viable alternative to Java Server Pages (JSPs) or PHP. Velocity also provides template services for the Turbine Web application framework, making a template service that allows Web applications to be developed according to a true MVC model.