CookSwing is a Java library that converts an XML document into Java Swing GUI at runtime. It is a tag library for CookXml, a general purpose XML parser. It was developed to be fast, extensible, and simple to use. There are many reasons to describe GUI layout using XML. You may ask why not a visual editor for Swing? In general, expert Swing developers are 10x if not more efficient than visual design. This is one of the main reasons why Swing visual editors never really took off. XML->GUI on the other hand can improves the efficiency creating a new layout or modifying an existing layout.