Basically useful to create a SWING interface for Java programs based on HTML tags: especially the GridBagLayout is fully implemented as <table> tag including colspan and rowspan attributes as well as align and valign to align the stuff.
The old Website xml4swing.sf.net is no longer available.
The code has moved to GitHub and SourceForce contains old code.
Note the code is now used in the WaveCleaner project and should be updated soon with some new functionalities. This is not dead code.