JavaServer Pages
JavaServer Pages (JSP) is a technology created by Sun Microsystems and closely tied to servlets. As with servlets, Sun releases a JSP specification, and third party vendors compete on their implementation of that standard. Being released by Sun puts JSPs in a very privileged position, and had JSP solved a sufficient number of user problems it would probably have won the market before there were any other viable entries. As is, a surprising number of users are disenchanted with JSP and alternatives are gaining popularity.

Tea is a newly open sourced product from the Walt Disney Internet Group, created internally over the years to solve their tremendous web production needs for sites such as It's similar to JSP although it avoids many of JSPs problems, and already has terrific tools support.

WebMacro is a template engine created by Semiotek as part of the Shimari project and now merged into the Apache Jakarta Project. WebMacro has been used on commercial sites such as, has been integrated in open source frameworks such as Turbine and Melati, and has been used in prominent open source projects such as JetSpeed.

Element Construction Set
The Element Construction Set (ECS) package from the Java Apache Project is a set of classes modeled after the htmlKona product from WebLogic (now BEA Systems). ECS has many limitations, but it solves a certain class of problems.

XMLC makes use of XML to get nearly all the power of ECS without many of its limitations. It was created by Lutris as part of their Open Source Enhydra Application Server, and can be used as a separate component.