This Editor was developed as a part of my Final Year Project along with my friend Ravi Pandit.
The entire code is written in Java. It uses Swing Api's for GUI and Xerces parser.
It has XML-HTML conversion feature, XML Well-Formity Check, Tree conversion, DTD and XSD validation.
We developed this editor in a week's span and this had one major bug: The conversion from tree to source code is inconsistent for few files. Since we haven't completed code for the "tree parse to xml" part, we ask its users to modify the code according to their usage.
In any case, I will be releasing the improvised code shortly. Download link is provided below.
Here are few screen shots:
or

December 20, 2011 9:23 PM
thankx friend....
am too doing the same project....