As a result, it usually takes a large and well-organized development shop to use them. This means that, although we now have a method for building large projects, medium-sized projects are still left out in the cold. The fact of the matter is that mid-sized projects represent the majority of Web applications. Thus, many projects are left to cope with a development and maintenance environment that does not meet their needs. Thankfully, JSP offers a solution.
Tag libraries provide a simple way to build reusable code blocks.
Finally tag libraries improve the maintainability of Web applications. This improved maintenance comes from the implementation of the simple XML-based interface of the custom tag on the JSP page. This opens up Web development to be a more effective team-based operation. The JSP programmer can build custom tags and background code modules while the Web designer can use the custom tags and concentrate on Web design. Tag libraries are the cure for spaghetti code and maybe even the common cold.